All Drugzzzzz Redo Exam 2 Flashcards
What is biotransformation for Dexedetomidine?
Biotransformation involves both direct glucuronidation and cytochrome P-450-mediated metabolism, with no active metabolites.
What is the onset of action for loading infusion of Dexedetomidine?
The onset of action with loading infusion is 10 to 20 minutes.
What is the duration of action after the Dexedetomidine infusion is stopped?
The duration of action after the infusion is stopped is 10 to 30 minutes.
What are the dosage parameters for dexmedetomidine?
Dexmedetomidine exhibits linear kinetics in the dosage range of 0.2 to 0.7 µg/kg/hour when administered by intravenous infusion for up to 24 hours.
What is the loading dose for dexmedetomidine?
The loading dose is 1 µg/kg infused over 10 minutes.
**Footnote
You can give IV, PO, intranasally, and spinally
What are the maintenance infusion rates for dexmedetomidine?
Maintenance infusions are 0.2 to 0.7 µg/kg/hour.
The induction dose of etomidate is typically
0.2-0.3 mg/kg.
How is Etomidate metabolized?
Etomidate is rapidly metabolized in the liver by hepatic microsomal enzymes and plasma esterases, primarily through ester hydrolysis, forming inactive carboxylic acid metabolites.
What percentage of Etomidate is excreted unchanged in urine?
Approximately 10% of the drug is excreted unchanged in the urine.
What is the terminal half-life of Etomidate?
The terminal half-life is 2 to 5 hours.
When does awakening typically occur after Etomidate administration?
Awakening typically occurs 5 to 15 minutes after bolus administration due to rapid redistribution to non-nervous sites.
What are the common side effects of etomidate?
Etomidate can cause pain on injection, thrombophlebitis, nausea, and vomiting.
The current formulation containing propylene glycol results in burning and pain on injection.
What is a common occurrence during the onset of etomidate use?
Myoclonia during onset is common with etomidate use.
In which patients is etomidate contraindicated?
Etomidate is contraindicated in patients with known sensitivity, adrenal suppression, and acute porphyrias.
How long does the effect of etomidate last?
The effect of etomidate lasts 24 hours.
What effect does etomidate have on blood pressure?
Etomidate causes an increase in blood pressure, which helps maintain myocardial oxygen supply and demand balance.
How does etomidate affect respiratory rate compared to propofol?
Etomidate causes an increase in respiratory rate, but the respiratory depression seen with etomidate is significantly less than that with propofol.
What receptors does ketamine antagonize?
Ketamine causes antagonism at N-methyl-D-aspartate (NMDA) receptors in the brain.
What system is responsible for the biotransformation of ketamine?
Hepatic microsomal enzyme systems are responsible for the biotransformation of ketamine.
What is the primary pathway for ketamine metabolism?
The primary pathway for ketamine metabolism by the cytochrome P-450 system is demethylation to form the metabolite norketamine.
How are ketamine metabolites eliminated?
These metabolites form a glucuronide derivative via conjugation, producing a more water-soluble compound that is eliminated primarily via renal excretion.
In what types of anesthesia is ketamine effective?
It is effective in obstetric and pediatric anesthesia, as well as for analgesia in combination with other agents like benzodiazepines and propofol.
What type of anesthesia does ketamine produce?
Ketamine produces a dissociative state of anesthesia, characterized by catalepsy, open eyes, reactive pupils, intact corneal reflexes, and horizontal nystagmus.
What are potential emergence reactions from ketamine?
It can cause emergence reactions, including vivid illusions and confusional disturbances.
How does ketamine affect the cardiovascular system?
Unlike other intravenous anesthetics, ketamine acts as a circulatory stimulant, increasing systemic blood pressure, heart rate, cardiac contractility and output, and central venous pressure.
What are the respiratory effects of ketamine?
The effects of ketamine on the respiratory system are minor and short-lived. Ventilation is generally preserved, and transient apnea may occur with rapid administration of larger doses.
How does ketamine affect cerebral blood flow?
Ketamine increases cerebral blood flow, cerebral metabolic rate, and intracranial pressure.
What type of analgesic effect does ketamine have? What do they preference?
It is a moderate analgesic with a preference for skin, bone, and joint pain.
What effect does ketamine have on seizure threshold?
Ketamine decreases seizure threshold.
What is ketamine’s role in respiratory?
Ketamine is a potent bronchodilator, preserving airway reflexes and increasing secretions.
What are some emergence phenomena associated with ketamine?
Emergence phenomena include vivid dreams, floating sensations, and delirium.
How does ketamine affect pregnancy?
Ketamine is highly lipid-soluble and readily crosses the placenta, producing rapid anesthesia without compromising uterine tone, uterine blood flow, or neonatal status at delivery.
What are the induction doses for ketamine?
Induction of Anesthesia: Ketamine 2-4 mg/kg IV, or 4-6 mg/kg IM (oral dose is 10 mg/kg).
What are the maintenance doses for ketamine?
Maintenance of Anesthesia: Ketamine 15-45 µg/kg/min (1-3 mg/min) by continuous IV infusion or 0.5-1.0 mg/kg supplemental IV doses as needed.
What are the sedation and analgesia doses for ketamine?
Sedation and Analgesia: Ketamine 0.2-0.8 mg/kg IV (over 2-3 min) followed by a continuous ketamine infusion (5-20 µg/kg/min). 10-20 mg may produce preemptive analgesia.
Ketamine is an indirect sympathomimetic, releasing
Catechloamines = cardiac stimulation and bronchodilation
What receptors does Propofol stimulate?
It directly stimulates GABA_A receptors.
What is the distribution time of Propofol following an intravenous bolus dose?
Rapid distribution occurs in 2 to 4 minutes.
What is the standard use of Propofol?
It is the standard agent for induction of general anesthesia and intravenous sedation.
How does Propofol affect electroconvulsive therapy (ECT)?
It reduces the duration of ECT-induced seizures without decreasing the efficacy of the therapy.
What is the typical induction dose of Propofol?
The induction dose is typically 1-2 mg/kg.
What is the maintenance infusion dose of Propofol?
The maintenance infusion is 100-200 µg/kg/min.
What are the doses for conscious sedation with Propofol?
Doses range from 25-75 µg/kg/min.
What effects does Propofol have on consciousness?
It produces a rapid and pleasant loss of consciousness and emergence from anesthesia.
What CNS effects does Propofol have?
It reduces cerebral blood flow, cerebral metabolic rate of oxygen consumption (CMRO2), and intracranial pressure (ICP).
What EEG changes are seen with higher doses of Propofol?
EEG data show a delta rhythm and burst suppression.
What is a potential use of Propofol in epilepsy?
It has been used to manage status epilepticus.
What is a common cardiovascular effect of Propofol?
It usually results in a mild to moderate transient decrease in blood pressure.
How does Propofol’s hypotensive effect compare to etomidate or midazolam?
The effects are more pronounced than those seen with equivalent doses of etomidate or midazolam.
What patient factors increase the risk of significant hypotension with Propofol?
Patients over 50 years old, with a baseline mean arterial pressure less than 70 mm Hg, or when coadministered with high doses of fentanyl.
What respiratory effects are associated with Propofol?
It causes transient respiratory depression, more prominent than that seen with etomidate.
What is a common respiratory effect following induction doses of Propofol?
Induction doses commonly lead to apnea.
What is Propofol Infusion Syndrome?
A serious condition associated with higher doses or prolonged infusions, symptoms include metabolic acidosis, hyperkalemia, lipidemia disorders, hepatomegaly, and elevated liver transaminases.
What are the antiemetic properties of Propofol?
It exhibits mild antiemetic properties.
What is a notable effect of Propofol upon emergence from sedation?
Patients emerge with mild euphoria with rapid dissipations of sedative effects.
What are the contraindications for Propofol?
It should not be used in patients with known hypersensitivity to propofol or its components, or in those with disorders of lipid metabolism.
What fetal effects can Propofol have during cesarean delivery?
It can cause sedative effects in the neonate and lower Apgar scores.
What movement effects can Propofol induce?
It may induce myoclonia, spontaneous excitatory movements.
What are the CNS effects of Midazolam?
Midazolam produces dose-dependent CNS depressant effects, ranging from anxiolysis to sedation, sleep, and anesthesia at high doses.
What additional properties does Midazolam have?
Midazolam has anticonvulsant effects, amnesia, and muscle-relaxing properties.
How does Midazolam affect seizure activity?
Midazolam increases the threshold to local anesthetic-induced seizure activity.
What type of amnesia does Midazolam produce?
Midazolam produces anterograde amnesia.
Why is Midazolam commonly used for preoperative medication?
It is commonly used due to its rapid onset, short duration, and half-life.
What roles does Midazolam serve in preoperative settings?
It is ideal as a preoperative anxiolytic, sedative, and amnestic.
What are the cardiovascular effects of Midazolam?
In clinical doses, midazolam has minimal cardiovascular effects, but a decrease in blood pressure may occur when combined with opioids.
What is a significant risk when using Midazolam?
The most common adverse effects are unexpected respiratory depression and oversedation.
In which patients should Midazolam be avoided?
Midazolam should be avoided in patients with acute porphyrias.
What is Flumazenil?
Flumazenil is the sole benzodiazepine antagonist, a competitive antagonist with a high affinity for the receptor site.
What is the purpose of Flumazenil?
It is used to reverse midazolam-induced sedation and suspected benzodiazepine overdose.
What is the onset and duration of action of Flumazenil?
Flumazenil’s onset is 1 to 2 minutes, and its duration of action is 45 to 90 minutes.
What are the effects of combining Midazolam with fentanyl?
Midazolam produces synergistic CNS, cardiovascular, and respiratory effects when combined with fentanyl.
How does Midazolam affect respiratory function?
Midazolam produces dose-dependent respiratory depression and is the most respiratory depressing among benzodiazepines.
What can increase respiratory depression when using Midazolam?
Increased respiratory depression and apnea are possible when combined with other CNS depressants.
What is the induction dose for Midazolam?
0.1-0.2 mg/kg
What effect do opioids have on pupils?
Opioids cause miosis (pinpoint pupils), especially under general anesthesia due to high doses of potent opiate.
How do opioids affect cough?
Opioids suppress cough via a depressant effect on the cough center in the medulla.
What effect do opioids have on nausea and vomiting?
Opioids elicit nausea and vomiting by stimulating the chemoreceptor trigger zone in the medulla’s area postrema.
What cardiovascular effects do opioids typically have?
Opioids typically result in bradycardia with little effect on blood pressure in healthy patients, due to medullary vagal stimulation.
What muscular effect can opioids cause?
Opioids can cause skeletal muscle rigidity.
What is a common side effect of neuraxial morphine?
Generalized itching is common with neuraxial morphine and can be treated with antihistamines or opiate receptor partial agonists or antagonists.
How do opioids affect the gastrointestinal system?
Opioids affect the gastrointestinal system, including constipation and urinary retention.
What hormonal effects do opioids have?
Opioids have hormonal effects, including the release of vasopressin and inhibition of stress-induced release of corticotropin and gonadotropins.
What routes can opioids be administered for pain control?
Opioids can be administered PO, IV, intrathecally or epidurally for pain control.
What is the biggest side effect of morphine?
Histamine release.
What is morphine primarily used for?
The abatement of moderate to severe pain.
Is morphine more effective for continuous dull pain or sharp intermittent pain?
Morphine is more effective in relieving continuous dull pain.
What occurs first when morphine is administered intravenously?
Sedation occurs first, followed by analgesia.
How lipophilic is morphine compared to other opioids?
Morphine is among the least lipophilic of the opioids.
What is the effect of morphine’s low lipophilicity?
It results in slow penetration of biologic membranes and slower onset.
How does morphine undergo metabolism in the liver?
Morphine undergoes phase 2 glucuronide conjugation at both the 3 and 6 positions.
What is the active metabolite of morphine?
Morphine-6-glucuronide (M6G).
What effect does M6G have in patients with renal failure?
It can prolong the therapeutic effects of morphine, often leading to excessive sedation.
How does M6G compare to morphine in the CNS?
M6G is more potent than the parent drug morphine.
What is the status of morphine-3-glucuronide (M3G)?
M3G is inactive.
What is the dosing range for morphine when administered intravenously?
0.05 to 0.15 mg/kg.
What is the onset time for morphine?
20 minutes.
What is the peak effect time for morphine?
30 to 60 minutes.
What is the duration of morphine’s effects?
4 to 5 hours.
What are the effects of Mu receptors?
• Strong analgesia, euphoria, sedation
• Respiratory depression
• Physical dependence & addiction potential
• Slowed gastrointestinal (GI) motility → constipation
What are the Kappa receptor effects?
• Moderate analgesia (less than mu)
• Dysphoria (opposite of euphoria)
• Diuresis (increased urination)
• Less respiratory depression than mu receptors
• Lower addiction potential
Addiction & Abuse Potential Differences for Mu and Kappa
• Mu receptors have high addiction potential due to their role in euphoria and reward.
• Kappa receptors have low addiction potential and may even have anti-addictive properties because they induce dysphoria.
Clinical difference between Mu and Kappa?
• Mu receptor drugs are widely used for pain management but carry a high risk of addiction and overdose.
• Kappa receptor drugs may be useful for pain relief with less abuse potential, but their dysphoric effects limit their use.
• Some mixed opioid agonists-antagonists (like buprenorphine) act on both receptors to balance analgesia and addiction risk.
What is the duration of action for a single administered dose of Fentanyl?
Approximately 20-40 minutes.
How is the action of a single dose of Fentanyl terminated?
By redistribution.
What property of Fentanyl allows for rapid tissue uptake?
High lipid solubility.
What is the IV intraoperative dose range for Fentanyl?
2-50 mcg/kg.
What is the IV postoperative dose range for Fentanyl?
0.5 - 1.5 mcg/kg.
What is the continuous infusion rate for Fentanyl?
25 to 100 mcg/hour for 24 to 72 hours.
What is the plasma concentration characteristic of Fentanyl during continuous infusion?
Relatively constant plasma concentration for 72 hours.
How does Fentanyl behave in the lungs?
Undergoes significant first-pass uptake with temporary accumulation before release.
What happens to the termination of action when Fentanyl is given in multiple doses or as a continuous infusion?
It reflects elimination and not redistribution.
How is Fentanyl metabolized?
By N-dealkylation and hydroxylation to inactive metabolites.
How are Fentanyl metabolites eliminated?
In urine and bile.
In which populations is Fentanyl elimination prolonged?
In the elderly and neonates.
What is Alfentanil?
Alfentanil is an opioid analgesic with a more rapid onset of action and shorter duration than Fentanyl, despite being less lipid-soluble.
What is the pharmacokinetics of Alfentanil?
The high nonionized fraction (90%) of Alfentanil at physiological pH and its small volume of distribution increase the amount of drug available for binding in the brain.
How is Alfentanil metabolized?
Alfentanil is metabolized in the liver by oxidative N-dealkylation and O-demethylation in the cytochrome P-450 system. The inactive metabolites are excreted in the urine.
What are the clinical uses of Alfentanil?
Alfentanil is effective epidurally, but its duration of analgesia is short, which has limited its popularity.
What drug interactions are associated with Alfentanil?
Erythromycin has been shown to prolong the metabolism of Alfentanil and interact with it to produce clinical symptoms of prolonged respiratory depression and sedation.
What is Hydromorphone?
Hydromorphone is a semisynthetic opioid derived from morphine.
What is the potency of Hydromorphone?
Hydromorphone is known for its high potency and is used in the management of pain.
What is the onset of action for Hydromorphone when administered IV?
The onset of action is 15 to 30 minutes.
When does the peak effect of Hydromorphone occur after IV administration?
The peak effect occurs between 30 to 90 minutes.
What is the duration of action for Hydromorphone?
The duration of action is 4 to 5 hours.
What is the half-life of Hydromorphone?
The half-life is approximately 1 to 3 hours.
What is the recommended dose of Hydromorphone?
The recommended dose is 0.01 to 0.02 mg/kg.
Why is Hydromorphone recommended for patients with renal failure?
Hydromorphone is safer for patients with renal failure due to the lack of any known active metabolites.
How does Hydromorphone compare to Morphine?
Studies show that parenteral Hydromorphone demonstrates similar analgesia and side effect profiles compared to Morphine.
What is Meperidine?
Meperidine is a synthetic mu receptor agonist, structurally similar to atropine, and possesses an antispasmodic effect similar to atropine.
What are the primary uses of Meperidine?
Meperidine is used for its analgesic properties.
How is Meperidine metabolized?
After demethylation in the liver, Meperidine is partially metabolized to normeperidine.
What is the analgesic potency of normeperidine compared to Meperidine?
Normeperidine is half as analgesic as Meperidine but lowers the seizure threshold and induces CNS excitability.
What is the elimination half-life of normeperidine?
The elimination half-life of normeperidine is significantly longer than that of Meperidine.
What clinical considerations are associated with normeperidine accumulation?
Accumulation of normeperidine can lead to CNS excitation characterized by tremors, muscle twitches, and seizures.
In which patients should Meperidine use be limited?
Limitations on Meperidine use should be considered in patients with renal failure, the elderly, and for chronic use in cancer patients who may require high doses.
What drug interactions are significant with Meperidine?
Significant drug interactions can occur between Meperidine and first-generation monoamine oxidase (MAO)-inhibiting drugs, leading to hyperthermia, seizures, and death.
How is Meperidine used in relation to shivering?
Meperidine is effective in reducing shivering from diverse causes, including general and epidural anesthesia.
What is the mechanism behind Meperidine’s effect on shivering?
This effect appears to result from kappa receptor stimulation, reducing visible shivering and the accompanying increase in histamine release.
What is the recommended dose of Meperidine?
The recommended dose is 12.5-25 mg/kg.
What is Remifentanil?
Remifentanil is a moderately lipophilic, piperidine-derived opioid with an ester link.
What is the significance of the ester link in Remifentanil?
The ester link allows the drug to be easily and rapidly metabolized by blood and tissue esterases.
What are the kinetic properties of Remifentanil?
Remifentanil has a small volume of distribution (Vd) and an elimination half-life of 8 to 20 minutes.
How is Remifentanil metabolized?
It is metabolized by hydrolysis to a less active compound and is not dependent on cholinesterase enzyme for metabolism.
Is bolus dosing of Remifentanil recommended?
Bolus dosing in the preoperative or postoperative care unit is not recommended due to the potential for respiratory depression and muscle rigidity.
What is the IV dose of Remifentanil?
IV dose = 1 mcg/kg
How potent is Alfentanil compared to morphine?
Approximately 10-25 times more potent than morphine.
How potent is Fentanyl compared to morphine?
About 50-100 times more potent than morphine.
How potent is Hydromorphone compared to morphine?
Roughly 5-7 times stronger than morphine.
How potent is Meperidine compared to morphine?
Generally considered less potent than morphine, with a ratio of about 1:10 (meperidine to morphine).
How potent is Remifentanil compared to morphine?
Extremely potent, with estimates ranging from 100-200 times more potent than morphine.
How potent is Sufentanil compared to morphine?
Around 500-1000 times more potent than morphine.
How potent is Alfentanil compared to Fentanyl?
Approximately 1/5 to 1/10 as potent as fentanyl.
How potent is Hydromorphone compared to Fentanyl?
Around 1/10 to 1/20 as potent as fentanyl.
How potent is Meperidine compared to Fentanyl?
Significantly less potent than fentanyl, approximately 1/75 to 1/100 as potent.
How potent is Morphine compared to Fentanyl?
Generally considered to be about 1/50 to 1/100 as potent as fentanyl.
How potent is Remifentanil compared to Fentanyl?
Roughly equivalent to fentanyl in potency, though it has a much shorter duration of action.
How potent is Sufentanil compared to Fentanyl?
About 5 to 10 times more potent than fentanyl.
What is Buprenorphine?
A potent partial agonist opioid that binds mainly to the mu receptors.
What is the duration of action for Buprenorphine?
Approximately 8 hours, due to its slow dissociation from the receptor.
What is the respiratory depression effect of Buprenorphine?
Exhibits a ceiling effect where an increase in dose does not increase respiratory depression.
What are the GI effects of Buprenorphine?
Minimal effect on GI motility and smooth muscle sphincter tone.
What is Buprenorphine commonly used for?
Commonly used in opioid use disorder treatment plans and for moderate to severe cancer pain through a transdermal system.
What is Butorphanol?
A highly lipophilic opioid, acting as an agonist at kappa receptors and a weak antagonist at mu receptors.
How does Butorphanol compare to morphine in terms of analgesia?
Can produce more analgesia than morphine but has a ceiling effect for respiratory depression below that of mu-agonists.
What is Butorphanol used for?
Used for the treatment of migraine headaches and postoperative pain, and has been studied for epidural use.
What is a notable side effect of Butorphanol?
Known to produce significant sedation.
What is Nalbuphine?
Acts as both an agonist and an antagonist at opioid receptors, with analgesic response equal to that of morphine.
What receptors does Nalbuphine target?
Provides an agonist effect at kappa receptors and an antagonist effect at mu receptors.
What is the respiratory depression effect of Nalbuphine?
Demonstrates a ceiling effect for respiratory depression and difficulty with reversal using naloxone.
What is Nalbuphine used for?
Used to antagonize pruritus induced by epidural and intrathecal morphine and effectively antagonizes fentanyl-induced respiratory depression without producing adverse circulatory changes.
What is Buprenorphine?
A potent partial agonist opioid that binds mainly to the mu receptors.
What is the duration of action for Buprenorphine?
Approximately 8 hours, due to its slow dissociation from the receptor.
What is the respiratory depression effect of Buprenorphine?
Exhibits a ceiling effect where an increase in dose does not increase respiratory depression.
What are the GI effects of Buprenorphine?
Minimal effect on GI motility and smooth muscle sphincter tone.
What is Buprenorphine commonly used for?
Commonly used in opioid use disorder treatment plans and for moderate to severe cancer pain through a transdermal system.
What is Butorphanol?
A highly lipophilic opioid, acting as an agonist at kappa receptors and a weak antagonist at mu receptors.
How does Butorphanol compare to morphine in terms of analgesia?
Can produce more analgesia than morphine but has a ceiling effect for respiratory depression below that of mu-agonists.
What is Butorphanol used for?
Used for the treatment of migraine headaches and postoperative pain, and has been studied for epidural use.
What is a notable side effect of Butorphanol?
Known to produce significant sedation.
What is Nalbuphine?
Acts as both an agonist and an antagonist at opioid receptors, with analgesic response equal to that of morphine.
What is the affinity of Buprenorphine?
Buprenorphine has a high affinity for mu receptors.
What are the actions of Nalbuphine?
Nalbuphine provides an agonist effect at kappa receptors and an antagonist effect at mu receptors.
What is the clinical use of Nalbuphine?
Nalbuphine is used for antagonizing pruritus and respiratory depression induced by other opioids.
What is Naloxone?
Naloxone is an oxymorphone derivative and a pure opioid antagonist.
How does Naloxone work?
It blocks opioid receptor sites, reversing respiratory depression and opioid analgesia through competitive antagonism at mu, kappa, and delta receptors.
What is the duration of action of Naloxone?
The duration of action of Naloxone is less than that of most opioid agonists.
What is a potential issue with Naloxone’s duration of action?
Patients treated with Naloxone may need to redose due to the return of respiratory depression.
How does Naltrexone compare to Naloxone?
Naltrexone has similar antagonist and receptor-binding properties but with higher oral efficacy and longer duration of action.
What is the duration of action of Naltrexone?
Approximately 24 hours.
What is the clinical uses of Naloxone?
It is routinely used in alcohol use disorder programs and administered to patients addicted to opioids to prevent euphoric effects.
What is Nalmefene?
Nalmefene is a long-acting parenteral opioid antagonist structurally similar to Naloxone.
What is the duration of action of Nalmefene?
It has an elimination half-life of approximately 10 hours and a duration of action of 8 hours when given in usual doses.
What is the use of Nalmefene?
Primarily used in alcohol use disorder programs.
What is the recommended dosage of Nalmefene in acute opioid overdose?
0.5 to 1.6 mg should be given intravenously.
What is Ketorolac?
An intravenous nonsteroidal anti-inflammatory drug (NSAID) used for mild to moderate pain. Primary advantages over opioids include a lack of significant GI and cardiovascular side effects.
What are the contraindications for Ketorolac?
Atopic or asthmatic patients, the elderly, patients with renal or GI dysfunction, or bleeding disorders.
What is Caldolor?
An intravenous formulation of Ibuprofen available as an analgesic and antipyretic.
What is the usual dose of Caldolor?
400 to 800 mg intravenously over 30 minutes, with an onset of 30 minutes and a duration of 4 to 6 hours.
What is Acetaminophen classified as?
An intravenous analgesic and antipyretic drug for use in both adults and children over 2 years old.
What is the dosage of Acetaminophen for patients over 13 years old?
1000 mg infused over 15 minutes.
What is the dosage of Acetaminophen for children?
15 mg/kg.
What are the side effects of Acetaminophen?
Rare, but hepatotoxicity is a concern with doses less than 4000 mg/day.
What type of receptor does nitrous oxide antagonize?
Nitrous oxide is an NMDA receptor antagonist.
How does nitrous oxide affect the sympathetic nervous system?
Nitrous oxide stimulates the sympathetic nervous system, which can mask its direct myocardial depressant effects in vivo.
What may happen to myocardial depression in patients with coronary artery disease or severe hypovolemia when using nitrous oxide?
Myocardial depression may be unmasked.
What are the respiratory effects of nitrous oxide?
Nitrous oxide increases respiratory rate and decreases tidal volume due to CNS stimulation, with minimal change in minute ventilation and resting arterial pCO2.
How does nitrous oxide affect the hypoxic drive?
It significantly depresses the hypoxic drive.
What are the cerebral effects of nitrous oxide?
Nitrous oxide increases cerebral blood flow (CBF) and cerebral blood volume, mildly elevating intracranial pressure and increasing cerebral oxygen consumption.
What is the analgesic effect of nitrous oxide?
It provides analgesia at concentrations below MAC for various procedures.
Does nitrous oxide provide significant muscle relaxation?
Nitrous oxide does not provide significant muscle relaxation and can cause skeletal muscle rigidity at high concentrations.
How does nitrous oxide affect kidney and hepatic blood flow?
It decreases kidney blood flow and glomerular filtration rate, and may reduce hepatic blood flow.
What is a risk associated with nitrous oxide use?
Nitrous oxide increases the risk of postoperative nausea and vomiting.
What is MAC in the context of anesthetics?
MAC is defined as the alveolar concentration of an inhaled anesthetic that prevents movement in 50% of patients in response to a standardized stimulus, such as a surgical incision.
Why is MAC a useful measure?
It reflects the partial pressure of the anesthetic in the brain, allowing for comparisons of potency between different anesthetic agents.
What is the approximate MAC needed to prevent movement in about 95% of patients?
Approximately 1.3 MAC of any volatile anesthetic prevents movement in about 95% of patients, approximating the EC95.
What MAC concentration is associated with awakening from anesthesia?
A concentration of 0.3 to 0.4 MAC is associated with awakening from anesthesia.
What does a low MAC indicate?
Low MAC = Potent anesthesia (needs less gas to work).
What does a high MAC indicate?
High MAC = Weak anesthesia (needs more gas to work).
What is the MAC for nitrous oxide?
Nitrous oxide MAC = 104.
What is the MAC for isoflurane?
Isoflurane MAC = 1.17.
What is the MAC for desflurane?
Desflurane MAC = 6.
What is the MAC for sevoflurane?
Sevoflurane MAC = 2.
What are the cardiovascular effects of isoflurane, sevoflurane, and desflurane?
All three anesthetics primarily cause a decrease in systemic vascular resistance and arterial blood pressure.
How do isoflurane and sevoflurane affect respiration?
Both depress respiration and act as bronchodilators.
What is the respiratory effect of desflurane?
Desflurane is an airway irritant.
What are the cerebral effects of isoflurane, sevoflurane, and desflurane?
All increase cerebral blood flow (CBF) and intracranial pressure, with sevoflurane and desflurane having similar effects on CBF autoregulation.
What are the neuromuscular effects of isoflurane and sevoflurane?
They provide muscle relaxation.
How does desflurane affect neuromuscular response?
Desflurane decreases response to peripheral nerve stimulation.
What are the renal and hepatic effects of isoflurane and sevoflurane?
They have similar effects on renal and hepatic systems. Minimal hepatic and renal effects, preserves organ blood flow, and is not associated with significant toxicity.
What is noted about the nephrotoxic effects of desflurane?
Desflurane is noted for minimal nephrotoxic effects.
How do the anesthetics differ in biotransformation and toxicity?
Isoflurane has limited oxidative metabolism, desflurane undergoes minimal metabolism, and sevoflurane has a higher rate of metabolism with potential nephrotoxic byproducts.
What are the contraindications and drug interactions of isoflurane, sevoflurane, and desflurane?
All three share similar contraindications and potentiate neuromuscular blocking agents (NMBAs).
What is a Single Twitch?
Involves a single supramaximal electrical stimulus ranging from 0.1-1.0 Hz. It requires a baseline before drug administration and is generally used as a qualitative assessment.
What is Train-of-Four (TOF)?
Consists of four twitches at 2 Hz every 0.5 sec for 2 sec. It reflects blockade from 70-100% and is useful during onset, maintenance, and emergence of neuromuscular blockade.
What is Double-Burst Stimulation (DBS)?
Involves two short bursts of 50-Hz tetanus separated by 0.75 sec. It’s similar to TOF and may be easier to detect fade than with TOF.
What is Tetanus?
Generally consists of rapid delivery of a 30-, 50-, or 100-Hz stimulus for 5 sec. It should be used sparingly for deep block assessment as it can be painful.
What is Posttetanic Count (PTC)?
Involves 50-Hz tetanus for 5 sec, a 3-sec pause, then single twitches of 1 Hz.
What is the TOF Ratio (TOFR)?
The size of the fourth twitch (T4) is compared to the first twitch (T1).
What does the disappearance of T4 indicate?
The disappearance of T4 represents a block of 75% to 80%.
What does the absence of T4 and T3 indicate?
The absence of T4 and T3 indicates an 80% to 85% block.
What does it suggest when T4, T3, and T2 are absent?
It suggests a 90% to 95% neuromuscular block (NMB).
What does 100% paralysis mean in terms of twitch responses?
100% paralysis is achieved when no responses can be elicited.
How long may successful reversal take with one response to TOF stimulation?
Successful reversal may take as long as 30 minutes.
What is the recovery time with a TOF count of two or three responses?
Recovery usually takes 4 to 15 minutes after intermediate-acting drugs.
What is the recovery time after the fourth twitch returns with neostigmine?
Adequate recovery can be achieved within 5 minutes of reversal with neostigmine.
What is the recovery time after the fourth twitch returns with edrophonium?
Adequate recovery can be achieved within 2 to 3 minutes after using edrophonium.
What is the standard TOFR that should be attained?
TOFR of 0.9 should be the standard attained.
Why is it important to achieve a TOFR of 0.9?
Even small degrees of residual block can increase the incidence of adverse respiratory events.
What type of ammonium is present in succinylcholine?
Succinylcholine contains a quaternary ammonium in its structure, making it water-soluble in the body.
Does succinylcholine pass the blood-brain barrier?
No, succinylcholine does not pass the blood-brain barrier and has no direct central nervous system (CNS) effects.
How does succinylcholine act on receptors?
Succinylcholine mimics the action of ACh by depolarizing the motor endplate.
What is the onset time for succinylcholine?
Succinylcholine has an extremely rapid onset, with effects usually within 3 minutes after administration.
Onset time is 30-60 seconds.
What is the clinical duration of succinylcholine?
The clinical duration of succinylcholine is 5 to 10 minutes.
What is the recommended bolus dose of succinylcholine?
The recommended bolus dose of succinylcholine is 0.5 to 1.5 mg/kg.
What cardiovascular effects can succinylcholine cause?
Succinylcholine can cause slight tachycardia or bradycardia, especially in children or with repeat dosing in adults. It may lead to various types of arrhythmias.
How is succinylcholine metabolized?
Succinylcholine is metabolized by plasma cholinesterase produced in the liver.
How does liver damage affect succinylcholine?
Liver damage may prolong the effects of the drug.
Can succinylcholine be used in patients with renal disease?
Yes, succinylcholine can be used in patients with renal disease if preoperative potassium levels are normal.
In which patients is succinylcholine contraindicated?
Succinylcholine is contraindicated in patients with elevated preoperative potassium levels.
What effect does succinylcholine have on intracranial pressure?
Succinylcholine indirectly increases intracranial pressure (ICP).
What is a common occurrence after succinylcholine administration?
Postoperative muscle pain, particularly in the face, subcostal region, trunk, neck, upper abdominal muscles, and shoulders.
What can prevent myalgia after succinylcholine administration?
Small doses of nondepolarizing muscle relaxants or pretreatment with sodium channel blockers or nonsteroidal anti-inflammatory drugs.
What effect does succinylcholine have on serum potassium levels?
Succinylcholine administration results in a transient increase in serum potassium levels.
In which patients can hyperkalemia be profound after succinylcholine administration?
In patients with burn injuries or underlying muscle disorders.
What is a contraindication for succinylcholine?
Succinylcholine is absolutely contraindicated in patients with known or suspected malignant hyperthermia (MH) or who have MH in their families.
What triggers malignant hyperthermia?
Malignant hyperthermia is triggered by volatile anesthetics, succinylcholine, and stress.
What is the twitch response in Phase I block?
In Phase I block, there is no fade in the response to tetanic or train-of-four (TOF) stimulation.
How does the twitch response differ in Phase II block?
Phase II block shows a fade in response, similar to that seen with nondepolarizing blockers.
Can Phase II blocks be reversed?
Yes, Phase II blocks can often be reversed with anticholinesterase drugs.
What is a key strategy regarding succinylcholine administration?
Avoiding excessive or repeated doses of drugs like succinylcholine is a key strategy.
What is the action of Rocuronium?
Rocuronium acts by competing with acetylcholine for binding to the nicotinic receptors at the motor endplate, leading to muscle relaxation. It does not depolarize the motor endplate or cause muscle fasciculations.
How is Rocuronium classified?
Rocuronium is classified as an intermediate-duration relaxant.
What is the duration of Rocuronium in usual ED95 doses?
In usual ED95 doses, Rocuronium lasts 30 to 60 minutes.
What is the onset time for Rocuronium?
The onset time for Rocuronium is 1 to 1.5 minutes.
How is Rocuronium eliminated from the body?
Rocuronium undergoes both hepatic and renal elimination, with biliary elimination of unchanged drug being the primary method.
What dosage of Rocuronium provides good intubating conditions?
Administration of Rocuronium with doses ranging from 0.6 to 1.2 mg/kg provides good to excellent intubating conditions within 45 to 90 seconds.
What precautions should be taken when administering Rocuronium?
Caution should be exercised in patients who are elderly and obese.
How does Rocuronium undergo deacetylation?
Rocuronium undergoes deacetylation via the liver.
What is the induction dose of vecuronium?
0.1 mg/kg
What is the onset time for vecuronium?
2-4 minutes
What is the duration of vecuronium?
30-60 minutes
What is the typical intubating dose of Cisatracurium?
The typical intubating dose of Cisatracurium is 0.1 mg/kg.
What is the time onset for Cisatracurium?
The time onset for Cisatracurium is 2-4 minutes.
What is the duration of action for Cisatracurium?
The duration of action for Cisatracurium is 30-60 minutes.
What is the dose of atracurium?
0.10 to 0.25 mg/kg
What side effects can atracurium cause?
Histamine release, which may produce hypotension and tachycardia.
What are the effects of atracurium at usual clinical doses?
Decreases in blood pressure and increases in heart rate due to histamine release.
How does atracurium pharmacokinetics compare in patients with hepatic and renal disease?
No differences in plasma elimination half-lives compared to nonimpaired control subjects.
What is the onset time for atracurium?
2-4 minutes
What is the duration of atracurium’s effects?
30-60 minutes
What is the minimum TOF count for spontaneous recovery at edrophonium administration?
The minimum TOF count should be at least 4.
What is the role of neostigmine in reversing neuromuscular blockade?
Neostigmine increases the concentration of endogenous ACh around cholinoreceptors to reverse neuromuscular blockade.
What are the risks associated with neostigmine administration?
Neostigmine may increase the incidence of postoperative nausea and vomiting.
Can neostigmine reverse deep neuromuscular blockade?
No, neostigmine does not reverse deep neuromuscular blockade and can lead to incomplete reversal.
What is the dose range for neostigmine?
The dose range for neostigmine is 25-75 mcg/kg.
What is the onset and duration of neostigmine?
Neostigmine has an onset of 5-15 minutes and a duration of 45-90 minutes.
What should be avoided when administering neostigmine?
Neostigmine should not be administered to patients with deep neuromuscular blockade.
What is the dosage range of sugammadex?
The dosage of sugammadex varies from 2 to 16 mg/kg depending on the depth of blockade at the time of reversal.
How is sugammadex administered?
It is administered as a single bolus injection.
What dose of sugammadex is recommended for spontaneous recovery with reappearance of the second twitch?
A dose of 2 mg/kg is recommended if spontaneous recovery has reached the reappearance of the second twitch or more in response to TOF stimulation.
What dose of sugammadex is recommended if there are 1 to 2 PTC responses?
A dose of 4 mg/kg is recommended if spontaneous recovery of the twitch response has reached 1 to 2 PTC and there are no twitch responses to TOF stimulation.
What dose of sugammadex is recommended for reversing NMB soon after rocuronium administration?
A dose of 16 mg/kg is recommended if there is a clinical need to reverse NMB soon after administration of a single dose of 1.2 mg/kg of rocuronium.
What are the most commonly reported adverse drug reactions of sugammadex?
The most commonly reported adverse drug reactions include nausea, vomiting, allergy, hypertension, and headache.
What serious reaction has been reported with sugammadex?
Anaphylaxis has been reported, which is the reason approval was initially delayed by the FDA.
What is the incidence of hypersensitivity to sugammadex?
Hypersensitivity to sugammadex appears to be relatively low, with only 15 cases reported in a recent review.
When do anaphylactic reactions typically occur after sugammadex administration?
In most cases, anaphylactic reactions were evident within the first 4 minutes after administration.
How was cardiovascular collapse treated in cases of anaphylaxis from sugammadex?
Cardiovascular collapse was treated successfully with fluid resuscitation and epinephrine therapy.
What special consideration should be taken regarding oral contraceptives and sugammadex?
Sugammadex binds oral contraceptives, and women of childbearing age should be counseled about using alternative contraceptive methods for 1 week after exposure to sugammadex.
What are atropine and glycopyrrolate used for?
They are used in combination with neostigmine or edrophonium to prevent the parasympathomimetic side effects of anticholinesterase drugs.
How does atropine compare to glycopyrrolate in terms of onset?
Atropine induces its vagolytic effect more rapidly than glycopyrrolate.
What is the usual recommended dose of atropine with edrophonium?
7 mcg/kg.
Why is glycopyrrolate used more often than atropine?
It produces less initial tachycardia and has no central nervous system effects.
What are the onset times for glycopyrrolate and neostigmine?
They have closely matched onset times.
How is atropine metabolized and excreted?
Atropine is metabolized by the liver into several metabolites and is excreted unchanged in the urine, expired air as carbon dioxide, and in feces.
How is glycopyrrolate absorbed and excreted?
Due to its ionization, glycopyrrolate has limited gastrointestinal absorption, blood-brain barrier, and placental penetration. It is excreted primarily in feces and urine, mostly as an unchanged drug.
What is the dose range for edrophonium?
500-1000 mcg/kg.
What is the onset time for edrophonium?
5-10 min.
What is the duration of edrophonium?
30-60 min.
What is the dose of Atropine?
15 mcg/kg
What is the onset time for Atropine?
1-2 min
What is the duration of Atropine’s effect?
1-2 hr
What is the dose of Glycopyrrolate?
10-20 mcg/kg
What is the onset time of Glycopyrrolate?
2 min
What is the duration of Glycopyrrolate?
2-4 hr
What is the dose of Suggammadex?
2-16 mg/kg
What is the onset time of Suggammadex?
1-2 min
What is the duration of Suggammadex?
2-16 hr
What is the dose of Glycopyrrolate?
10-20 mcg/kg
What is the onset time of Glycopyrrolate?
2 min
What is the duration of Glycopyrrolate?
2-4 hr
What is the dose of Suggammadex?
2-16 mg/kg
What is the onset time of Suggammadex?
1-2 min
What is the duration of Suggammadex?
2-16 hr
What receptors does ephedrine stimulate?
Ephedrine stimulates both alpha and beta receptors directly and indirectly causes the release of endogenous catecholamines.
What are the intravenous dose ranges for ephedrine?
Intravenous doses range from 5 to 25 mg.
What is the onset and duration of action for ephedrine?
Ephedrine has an immediate onset and a duration of action of 15 minutes to 1.5 hours, depending on the dose.
In which patients should ephedrine be used cautiously?
Ephedrine should be used cautiously in patients with questionable coronary perfusion.
What effect does ephedrine have on myocardial oxygen consumption?
Ephedrine can dramatically increase myocardial oxygen consumption.
What is the effect of ephedrine on the lungs?
Ephedrine causes bronchodilation due to beta2 receptor agonism in the lungs.
What was ephedrine’s role in obstetrics?
Ephedrine was long considered the drug of choice for maternal hypotension after regional anesthesia.
What recent data suggests about the use of ephedrine in obstetrics?
Recent data suggest phenylephrine may be a better option than ephedrine for maternal hypotension.
What receptors does ephedrine stimulate?
Ephedrine stimulates both alpha and beta receptors directly and indirectly causes the release of endogenous catecholamines.
What are the intravenous dose ranges for ephedrine?
Intravenous doses range from 5 to 25 mg.
What is the onset and duration of action for ephedrine?
Ephedrine has an immediate onset and a duration of action of 15 minutes to 1.5 hours, depending on the dose.
In which patients should ephedrine be used cautiously?
Ephedrine should be used cautiously in patients with questionable coronary perfusion.
What effect does ephedrine have on myocardial oxygen consumption?
Ephedrine can dramatically increase myocardial oxygen consumption.
What is the effect of ephedrine on the lungs?
Ephedrine causes bronchodilation due to beta2 receptor agonism in the lungs.
What was ephedrine’s role in obstetrics?
Ephedrine was long considered the drug of choice for maternal hypotension after regional anesthesia.
What recent data suggests about the use of ephedrine in obstetrics?
Recent data suggest phenylephrine may be a better option than ephedrine for maternal hypotension.
What is Phenylephrine (Neo-Synephrine)?
Phenylephrine is a pure alpha-agonist with strong alpha-stimulating effects and virtually no beta receptor stimulation.
What effect does Phenylephrine have on blood pressure?
It causes a significant increase in peripheral resistance due to alpha1 stimulation, leading to a sharp rise in blood pressure.
What is a common side effect of Phenylephrine?
A reflex bradycardia is commonly elicited secondary to baroreceptor stimulation.
What is the onset and duration of intravenous Phenylephrine?
Intravenous phenylephrine has an immediate onset of action, with a duration ranging from 5 to 20 minutes.
What is necessary when administering Phenylephrine?
Careful titration is necessary to avoid large changes in blood pressure and decreases in heart rate.
What are the topical uses of Phenylephrine?
It is used topically to prevent nosebleeds during nasal intubation or to reduce bleeding during ear, nose, and throat surgery.
How is Phenylephrine used in ophthalmology?
It is used as a mydriatic in ophthalmology.
What potential side effect should be monitored with Phenylephrine?
Due to its potent vasoconstricting effects, hypertension may occur, and careful dose titration should be observed.
What is the recommendation for Phenylephrine in obstetrics?
Phenylephrine is now recommended over ephedrine for addressing maternal hypotension after regional anesthesia, as it is felt to maintain uterine blood flow better.
What is Phenylephrine (Neo-Synephrine)?
Phenylephrine is a pure alpha-agonist with strong alpha-stimulating effects and virtually no beta receptor stimulation.
What effect does Phenylephrine have on blood pressure?
It causes a significant increase in peripheral resistance due to alpha1 stimulation, leading to a sharp rise in blood pressure.
What is a common side effect of Phenylephrine?
A reflex bradycardia is commonly elicited secondary to baroreceptor stimulation.
What is the onset and duration of intravenous Phenylephrine?
Intravenous phenylephrine has an immediate onset of action, with a duration ranging from 5 to 20 minutes.
What is necessary when administering Phenylephrine?
Careful titration is necessary to avoid large changes in blood pressure and decreases in heart rate.
What are the topical uses of Phenylephrine?
It is used topically to prevent nosebleeds during nasal intubation or to reduce bleeding during ear, nose, and throat surgery.
How is Phenylephrine used in ophthalmology?
It is used as a mydriatic in ophthalmology.
What potential side effect should be monitored with Phenylephrine?
Due to its potent vasoconstricting effects, hypertension may occur, and careful dose titration should be observed.
What is the recommendation for Phenylephrine in obstetrics?
Phenylephrine is now recommended over ephedrine for addressing maternal hypotension after regional anesthesia, as it is felt to maintain uterine blood flow better.
What is Esmolol?
Esmolol is a selective beta-blocker with a rapid onset and short duration of action.
What is the onset time of Esmolol?
Esmolol has an onset time of 2 minutes.
What is the elimination half-life of Esmolol?
The elimination half-life of Esmolol is approximately 9 minutes.
What is the duration of action of Esmolol?
The duration of action of Esmolol is 10 to 15 minutes.
How is Esmolol metabolized?
Esmolol is metabolized by nonspecific plasma esterases found in the cytosol of red blood cells.
What is the recommended IV loading dose of Esmolol?
The recommended intravenous (IV) loading dose of Esmolol is 500 mcg/kg.
What is the infusion rate for Esmolol after loading?
The infusion rate for Esmolol is 100 to 300 mcg/kg/min as needed.
What are the small bolus doses for Esmolol?
Small boluses of 10 to 20 mg may be given, with administration repeated according to patient response.
Why is Esmolol particularly useful in the perioperative period?
Esmolol is particularly useful in the perioperative period due to its rapid onset and short duration of action.
What does Esmolol replace in anesthesia?
Esmolol replaces propranolol in most instances of beta-blocker application in anesthesia.
What is Esmolol?
Esmolol is a selective beta-blocker with a rapid onset and short duration of action.
What is the onset time of Esmolol?
Esmolol has an onset time of 2 minutes.
What is the elimination half-life of Esmolol?
The elimination half-life of Esmolol is approximately 9 minutes.
What is the duration of action of Esmolol?
The duration of action of Esmolol is 10 to 15 minutes.
How is Esmolol metabolized?
Esmolol is metabolized by nonspecific plasma esterases found in the cytosol of red blood cells.
What is the recommended IV loading dose of Esmolol?
The recommended intravenous (IV) loading dose of Esmolol is 500 mcg/kg.
What is the infusion rate for Esmolol after loading?
The infusion rate for Esmolol is 100 to 300 mcg/kg/min as needed.
What are the small bolus doses for Esmolol?
Small boluses of 10 to 20 mg may be given, with administration repeated according to patient response.
Why is Esmolol particularly useful in the perioperative period?
Esmolol is particularly useful in the perioperative period due to its rapid onset and short duration of action.
What does Esmolol replace in anesthesia?
Esmolol replaces propranolol in most instances of beta-blocker application in anesthesia.
What type of drug is Metoprolol?
Metoprolol is a selective beta blocking drug.
In what form is Metoprolol available?
Metoprolol is available in intravenous (IV) form.
When is Metoprolol particularly useful?
Metoprolol is particularly useful in the perioperative period.
What are the beta-blocking effects of Metoprolol?
The beta-blocking effects include negative chronotropic, dromotropic, inotropic, antiarrhythmic, and antiischemic actions.
When is Metoprolol used after myocardial infarction?
Metoprolol is used after myocardial infarction (MI) or in some types of angina and hypertension once the patient is stable.
What is the recommended IV administration for Metoprolol?
The recommended IV administration is 5-mg doses at 5-minute intervals to a maximum dose of 15 mg.
What are the other beta-adrenergic blocking agents useful in the perioperative period?
Esmolol and Labetalol are the other two beta-adrenergic blocking agents.
What is the typical oral dosage range for Metoprolol?
Metoprolol is typically prescribed in the range of 50-200 mg in one or two doses.
What is the dosage range for extended-release Metoprolol?
The extended-release form is available in dosages of 25-400 mg once daily.
What type of beta-blocker is labetalol?
Labetalol is classified as a nonselective beta-blocker with an alpha-blocking component.
What is the ratio of beta-blockade to alpha-blockade in labetalol?
Labetalol provides beta-blockade along with alpha-blockade in a ratio of 7:1.
What is a unique effect of labetalol compared to standard beta-blockers?
Labetalol produces vasodilation due to its alpha-blocking properties.
What is the usual IV dose of labetalol?
The usual IV dose of labetalol is 0.25 mg/kg, which can be repeated as indicated.
What is the infusion rate for labetalol if necessary?
The infusion rate for labetalol, if necessary, is 2 mg/min.
In which patients is labetalol recommended for hypertensive episodes?
Labetalol is recommended for hypertensive episodes in obstetric patients.
How does labetalol affect uterine blood flow?
Uterine blood flow is not affected by labetalol even with a decrease in systemic blood pressure.
How is labetalol metabolized and eliminated?
Labetalol undergoes hepatic metabolism and renal elimination.
What is the duration of action for labetalol?
The duration of action for labetalol ranges from 2 to 6 hours depending on the dose.
What is a contraindication for the use of labetalol?
Preexisting bradycardia is a contraindication for its use in the acute management of hypertension.
What type of beta-blocker is labetalol?
Labetalol is classified as a nonselective beta-blocker with an alpha-blocking component.
What is the ratio of beta-blockade to alpha-blockade in labetalol?
Labetalol provides beta-blockade along with alpha-blockade in a ratio of 7:1.
What is a unique effect of labetalol compared to standard beta-blockers?
Labetalol produces vasodilation due to its alpha-blocking properties.
What is the usual IV dose of labetalol?
The usual IV dose of labetalol is 0.25 mg/kg, which can be repeated as indicated.
What is the infusion rate for labetalol if necessary?
The infusion rate for labetalol, if necessary, is 2 mg/min.
In which patients is labetalol recommended for hypertensive episodes?
Labetalol is recommended for hypertensive episodes in obstetric patients.
How does labetalol affect uterine blood flow?
Uterine blood flow is not affected by labetalol even with a decrease in systemic blood pressure.
How is labetalol metabolized and eliminated?
Labetalol undergoes hepatic metabolism and renal elimination.
What is the duration of action for labetalol?
The duration of action for labetalol ranges from 2 to 6 hours depending on the dose.
What is a contraindication for the use of labetalol?
Preexisting bradycardia is a contraindication for its use in the acute management of hypertension.
What is atropine?
Atropine is a belladonna alkaloid and the prototype anticholinergic used for its antisialagogue effects, prevention or treatment of bradycardia, and in conjunction with anticholinesterase agents in the reversal of muscle relaxants.
What is the usual adult IV dose of atropine for increasing heart rate during anesthesia?
The usual adult IV dose for increasing heart rate during anesthesia is 0.4 to 0.6 mg, with an onset time of 1 to 2 minutes.
What type of amine is atropine?
Atropine is a tertiary amine, allowing it to cross the blood-brain barrier. However, significant CNS effects are rarely evident at usual clinical doses.
What is scopolamine?
Scopolamine is a belladonna alkaloid with anticholinergic effects.
What are the uses of scopolamine?
It is used as a preoperative medication for sedation and amnesia, and to diminish the incidence of postoperative nausea and vomiting.
How is scopolamine administered?
A scopolamine patch containing a total dose of 1.5 mg is applied behind the ear 4 hours prior to anesthesia.
What is the clinical duration of action for scopolamine?
The clinical duration of action is 3 days.
What is scopolamine?
Scopolamine is a belladonna alkaloid with anticholinergic effects.
What are the uses of scopolamine?
It is used as a preoperative medication for sedation and amnesia, and to diminish the incidence of postoperative nausea and vomiting.
How is scopolamine administered?
A scopolamine patch containing a total dose of 1.5 mg is applied behind the ear 4 hours prior to anesthesia.
What is the clinical duration of action for scopolamine?
The clinical duration of action is 3 days.
What type of antibiotic is Cefazolin?
Cefazolin is a β-lactam antibiotic.
What is the primary mechanism of action of Cefazolin?
Cefazolin works primarily via time-dependent killing.
What is the usual adult dosage of Cefazolin?
The usual adult dosage is 2g IV.
When should Cefazolin be administered before surgery?
Cefazolin should be given as a single IV dose within 60 minutes before incision.
What is the recommended duration of antimicrobial prophylaxis for most procedures?
The duration of antimicrobial prophylaxis should be less than 24 hours for most procedures.
What alternatives are suggested for patients allergic to β-lactams?
Alternatives like vancomycin or clindamycin are suggested.
What is Dexamethasone commonly used for?
Dexamethasone is popular for Post Operative Nausea and Vomiting (PONV) prevention.
What is the recommended dose of Dexamethasone for PONV prevention?
The recommended dose is 4 mg IV after anesthesia induction.
What effect does Dexamethasone have on blood glucose?
Dexamethasone can increase blood glucose.
When is Dexamethasone most effective for decreasing PONV?
It is effective when administered prior to anesthesia induction.
What is the duration of action of Dexamethasone?
The duration of action is approximately 72 hours.
What is Dexamethasone commonly used for?
Dexamethasone is popular for Post Operative Nausea and Vomiting (PONV) prevention.
What is the recommended dose of Dexamethasone for PONV prevention?
The recommended dose is 4 mg IV after anesthesia induction.
What effect does Dexamethasone have on blood glucose?
Dexamethasone can increase blood glucose.
When is Dexamethasone most effective for decreasing PONV?
It is effective when administered prior to anesthesia induction.
What is the duration of action of Dexamethasone?
The duration of action is approximately 72 hours.
What is the effective dose of Methylprednisolone for nausea and vomiting prophylaxis?
40 mg IV is effective for nausea and vomiting prophylaxis.
What is Ondansetron known for?
Most widely used antiemetic, more effective for vomiting than nausea. Standard dose is 4 mg IV at the end of the procedure. Known for minimal side effects, but higher doses can affect the QT interval.
What is the duration of action for Ondansetron?
Short duration of action (4-6 hours) limits effectiveness for Post Discharge Nausea and Vomiting (PDNV).
How does the efficacy of Ondansetron change when combined with dexamethasone?
Efficacy increases when combined with dexamethasone.
What are other 5-HT3 antagonists mentioned?
Include granisetron and dolasetron. Palonosetron, with a longer half-life of 44 hours, is preferable for PDNV.
What is the dosage of Droperidol for PONV prevention and treatment?
Used in doses of 0.625 to 1.25 mg IV for PONV prevention and treatment.
What is the mechanism of action for Droperidol?
Acts as a dopamine receptor blocker in the CNS.
What are the side effects of Droperidol?
May cause extrapyramidal side effects and is contraindicated in Parkinson’s disease.
Why has the usage of Droperidol decreased in the U.S.?
Due to FDA warnings about QT interval prolongation.
What are the antiemetic properties of Haloperidol?
Has antiemetic properties at low doses (1-2 mg). Used as an alternative to droperidol despite similar QT interval effects.
When is Transdermal Scopolamine most effective?
Effective when applied the evening before surgery.
How does Transdermal Scopolamine prevent nausea and vomiting?
By blocking cholinergic impulses.
What are the side effects of Transdermal Scopolamine?
Include sedation, blurred vision, dizziness, and dry mouth.
What is the effectiveness of Transdermal Scopolamine for postoperative pain?
Most effective for nausea prevention with patient-controlled analgesia for postoperative pain.
What is the role of Midazolam in antiemetic therapy?
Recent studies suggest a significant antiemetic effect.
How does Midazolam exert its antiemetic effect?
Decreases dopamine’s emetic effect in the chemoreceptor trigger zone and decreases serotonin release by binding to the GABA receptor complex.
What is a potential drawback of using Midazolam as a sedative?
Use as a sedative near the end of surgery may prolong recovery.
What is the effectiveness of Metoclopramide as an antiemetic?
A weak antiemetic with mild dopamine receptor blocking effect.
What is the effective dose of Metoclopramide?
Effective doses are greater than 20 mg.
What limits the effectiveness of Metoclopramide if given at the beginning of surgery?
Short half-life (30-45 minutes).
What are the risks associated with higher doses of Metoclopramide?
Can cause dyskinesia or extrapyramidal effects and is contraindicated in Parkinson’s disease and intestinal obstructions.
What should be considered for patients at moderate to high risk for PONV?
Multimodal PONV and PDNV prophylaxis should be considered.
What is recommended for children at moderate or high risk for PONV?
Combination therapy using a 5-HT3 antagonist and a second drug is recommended.
What should be done if PONV occurs within 6 hours postoperatively?
A repeat dose of the prophylactic antiemetic should not be given.
What is the effective dose of Methylprednisolone for nausea and vomiting prophylaxis?
40 mg IV is effective for nausea and vomiting prophylaxis.
What is Ondansetron known for?
Most widely used antiemetic, more effective for vomiting than nausea. Standard dose is 4 mg IV at the end of the procedure. Known for minimal side effects, but higher doses can affect the QT interval.
What is the duration of action for Ondansetron?
Short duration of action (4-6 hours) limits effectiveness for Post Discharge Nausea and Vomiting (PDNV).
How does the efficacy of Ondansetron change when combined with dexamethasone?
Efficacy increases when combined with dexamethasone.
What are other 5-HT3 antagonists mentioned?
Include granisetron and dolasetron. Palonosetron, with a longer half-life of 44 hours, is preferable for PDNV.
What is the dosage of Droperidol for PONV prevention and treatment?
Used in doses of 0.625 to 1.25 mg IV for PONV prevention and treatment.
What is the mechanism of action for Droperidol?
Acts as a dopamine receptor blocker in the CNS.
What are the side effects of Droperidol?
May cause extrapyramidal side effects and is contraindicated in Parkinson’s disease.
Why has the usage of Droperidol decreased in the U.S.?
Due to FDA warnings about QT interval prolongation.
What are the antiemetic properties of Haloperidol?
Has antiemetic properties at low doses (1-2 mg). Used as an alternative to droperidol despite similar QT interval effects.
When is Transdermal Scopolamine most effective?
Effective when applied the evening before surgery.
How does Transdermal Scopolamine prevent nausea and vomiting?
By blocking cholinergic impulses.
What are the side effects of Transdermal Scopolamine?
Include sedation, blurred vision, dizziness, and dry mouth.
What is the effectiveness of Transdermal Scopolamine for postoperative pain?
Most effective for nausea prevention with patient-controlled analgesia for postoperative pain.
What is the role of Midazolam in antiemetic therapy?
Recent studies suggest a significant antiemetic effect.
How does Midazolam exert its antiemetic effect?
Decreases dopamine’s emetic effect in the chemoreceptor trigger zone and decreases serotonin release by binding to the GABA receptor complex.
What is a potential drawback of using Midazolam as a sedative?
Use as a sedative near the end of surgery may prolong recovery.
What is the effectiveness of Metoclopramide as an antiemetic?
A weak antiemetic with mild dopamine receptor blocking effect.
What is the effective dose of Metoclopramide?
Effective doses are greater than 20 mg.
What limits the effectiveness of Metoclopramide if given at the beginning of surgery?
Short half-life (30-45 minutes).
What are the risks associated with higher doses of Metoclopramide?
Can cause dyskinesia or extrapyramidal effects and is contraindicated in Parkinson’s disease and intestinal obstructions.
What should be considered for patients at moderate to high risk for PONV?
Multimodal PONV and PDNV prophylaxis should be considered.
What is recommended for children at moderate or high risk for PONV?
Combination therapy using a 5-HT3 antagonist and a second drug is recommended.
What should be done if PONV occurs within 6 hours postoperatively?
A repeat dose of the prophylactic antiemetic should not be given.
