Pharm Flashcards
Exam II
A drug that reversibly depresses the activity of the CNS
Sedative-Hypnotics
A drug that reduces anxiety and that has sedation as a side effect
Anxiolytic
What are Vessel-poor groups? What % of CO do they receive?
- Bone
- Tendon
- Cartilage; 2%
Fat recieves how much CO?
5%
What muscle groups receive how much CO? What %?
- Skeletal muscle
- Skin; 18%
What are the vessel-rich groups? What % of CO do they receive?
- Brain
- Heart
- Kidney
- Liver ; 75%
What are the 4 stages of general anesthesia?
- Analgesia
- Delirium
- Surgical Anesthesia
- Medullary Paralysis
What are the 5 components of general anesthesia?
- Hypnosis
- Analgesia
- Muscle Relaxation
- Sympatholysis
- Amnesia
It starts with the initiation of an anesthetic agent and ends with the loss of conciousness
Stage 1: Analgesia
It starts with the loss of consciousness to the onset of automatic rhythmicity of vital signs.
Stage 2: Delirium
It starts with the absence of response to surgical incision and depression in all elements of nervous system function.
Stage 3: Surgical Anesthesia
It starts with cessation of spontaneous respiration and medullary cardiac reflexes.
Stage 4: Medullary Paralysis
The lightest level of anesthesia
Stage 1: Analgesia
Rapid stage that is chracterized by excitement, movements, laryngospasm, and emesis
Stage 2: Delirium
Stage associated with flaccid paralysis, absent reflexes, and marked hypotension with a weak, irregular pulse
Stage 4: Medullary Paralysis
What are the 4 induction drugs?
- Barbituates
- Propofol
- Etomidate
- Ketamine
What drug is the gold standard for comparison with other drugs?
Barbituates
What is the MoA of Barbituates?
Potentiate GABAA channel activity; directly mimics GABA
What other receptors do barbituates work on besides GABAA?
- Glutamate
- Adenosine
- Neural nACh
Barbiturates are cerebral vaso_____. They ______ CBF and ______ CRMO2 by 55%
vasoconstrictors; decrease; decrease
Barbituates have a lengthy…
context-sensitive half-time
Barbiturates have a ____ onset & _____ awakening d/t ____ uptake and ____ redistribution
rapid; rapid; rapid; rapid
How are barbituates dosed?
Dosed on LEAN body weight
What is the primary metabolism mechanism for barbituates?
Liver Hepatocytes
What drug is given rectally with uncooperative/young patients?
Barbituates
Which barbituates are the thiobarbituates?
- Thiopental
- Thiamylal
Which barbiturates are the oxybarbiturates?
- Methohexital
- Phenobarbital
- Pentobarbital
What is the dose for Thiopental (Sodium Pentothal)? How is the dose calculated?
4 mg/kg IV; IBW
Describes the distribution of a given agent at equilibrium between two substances at the same temperature, pressure, and volume
Partition Coefficients
Describes the distribution of an anesthetic between blood and gas at the same partial pressure
Blood-gas coefficient
Which barbiturates have oxygen in the second position?
Oxybarbiturates
What gives thiobarbiturates more hypnotic potency and lipid solubility?
Sulfur atom in place of the oxygen atom in the second position.
What are two side effects of methohexital?
- Myoclonus
- Hiccoughs
What is the dose for Methohexital (Brevital)
1.5 mg/kg IV
What are the primary CV effects of barbiturates?
- Lack of baroreceptor response
- Histamine release - anaphylactoid response with previous exposure
- Transient decreases in BP
- Trainsent increase in HR
What are the primary respiratory effects of barbituates?
Dose-dependent depression of ventilatory centers
Results in immediate, intense vasoconstriction and excruciating pain that radiates along the distribution of the artery
Intra-arterial injection of barbiturates
What’s the antidote for an intra-arterial injection of barbiturates?
Licodaine or papaverine
What is the MoA for propofol?
GABA receptor agonist
What’s the induction dose for propofol?
1.5-2.5 mg/kg IV
What’s the conscious sedation dose of propofol?
25-100 mcg/kg/min
What is the constitution of a 1% solution of propofol?
- Soybean oil (10%)
- Glycerol (2.25%)
- Purified egg phosphatide (1.2%)
What are the 3 primary disadvantages of propofol?
- Support bacterial growth
- Causes increased plasma triglyceride concentrations
- Pain on injection
What happens when propofol binds to a GABAA receptor?
Transmembrane chloride conductance increases
What is the elimination 1/2 time of propofol?
0.5-1.5 hours
A low lipid emulsion with no preservative and higher incidence of pain on injection.
Ampofol
What are 3 potential contraindications or precautions with propofol use?
- Cirrhosis of the liver
- Renal dysfunction
- Pregnancy and the neonate
What are the two primary uses for propofol?
- Induction
- TIVA
Why do children require a higher dose of propofol?
Larger central distribution volume and faster clearance rate
- Minimal analgesic and amnestic effects
- Prompt recovery without residual sedation
- Low incidence of PONV
- Anticonvulsant
- Bronchodilation
Benefits of propofol
What are two notable case types that benefit from propofol use?
- Agent of choice in GI endoscopy procedures
- Mechanically ventilated patients in the ICU or postop (cardiac, neuro, etc.)
What is the MoA for propofol’s antiemetic effects?
It depresses subcortical pathways and has a direct depressant effect on the vomiting center
What’s the sub-hypnotic dose of propofol? Anti-pruritic?
10-15 mg IV followed by 10mcg/kg/min; 10mg
What are the 3 primary CNS effects of propofol?
- Decreases CRMO2, CBF, and ICP
- Larger doses decrease CPP
- Myoclonus
How does propofol cause its vasodilatory effects?
Inhibition of the SNS and decreases intracellular Ca2+
What does the green and cloudy urine from propofol come from?
- Phenols (Green)
- Uric acid crystallization (Cloudy)
What are two severe side effects of propofol?
- Profound bradycardia and asystole in healthy adult patients
- Severe, refractory, and fatal bradycardia in children
What causes pain at the injection site with etomidate?
Propylene glycol
What’s the onset for Etomidate?
1 min
What’s the dose for Etomidate?
0.3mg/kg
What’s the MoA for Etomidate?
Selective modulator of GABAA receptors
What is the best patient population to use Etomidate with?
Patient’s with unstable CV system
What are two of the primary side effects of Etomidate?
- Myoclonus
- Adrenocortical Suppression
How often does myoclonus happen in patients given Etomidate?
50-80%
What are two contraindications to using etomidate?
- Sepsis
- Hemorrhage
How is Etomidate metabolized?
Hydrolysis by hepatic microsomal enzymes and plasma esterases
What happens with adrenocortical suppression?
- No stress response (no cortisol)
- Enzyme inhibition for 4-8 hours
- Severe hypotension
- Longer mechanical ventilation
Fentanyl 50mcg/mL is available. Patient is 75kg. Administer 1mcg/kg to attenuate myoclonus. How many mLs will you administer?
1.5 mLs
What is ketamine a derivative of?
PCP
It resembles a cataleptic state in which eyes remain open with a slow nystagmic gaze. The patient is uncommunicative, but wakefulness is present. Purposeful movement.
Dissociative anesthesia
What is the preservative in ketamine?
Benzethonium Chloride
What is the MoA for Ketamine?
Inhibit uptake of catecholamines back into the postganglionic sympathetic nerve endings
What receptors to ketamine bind to?
N-Methyl-D-aspartate (NMDA) receptors
What is the most abundant excitatory neurotransmitter in CNS?
Glutamate
What are the pharmacokinetics of Ketamine?
- Rapid onset
- Short duration of action
- Large Vd - highly lipid soluable
How long does ketamine last?
10-20 minutes
When is ketamine’s peak plasma concentration?
1 minute
What is norketamine?
Active metabolite of Ketamine (1/3 potency)
What is the induction dose for ketamine?
0.5-1.5 mg/kg IV
What is the subanesthetic dose for Ketamine?
0.2-0.5 mg/kg IV
What induction drug has weak actions at GABAA receptors?
Ketamine
Besides NMDA, what are the other receptors that Ketamine works on?
- Mu
- Kappa
- Delta
What are the neuraxial doses of Ketamine?
30 mgs Epidural
5-50 mg in 3mLs of saline intrathecal/spinal
Ketamine 25mgs/mL is available. How much diluent should be used to decrease the concentration to 5mgs/mL?
4 mLs
What is the coronary artery disease cocktail?
- Diazepam 0.5mg/kg IV
- Ketamine 0.5 mg/kg IV
- Continuous ketamine infusion mcg/kg/min
What are some of the nonanesthesia clinical uses for ketamine?
- Burn dressing, debridement, grafting
- Psychiatric disorders
- Reversal of opioid tolerance
What are the contraindications for ketamine?
- PHTN
- Increased ICP
What are some issues ketamine can cause during induction? How are they prevented/treated?
Coughing and laryngospasm; give an antisialoagogue or Glycopyrrolate
With Ketamine ventilatory response to CO2is ___________ .
maintained/unchanged
Ketamine is a potent cerebral vaso________.
Vasodilator
What should be given 5 minutes before emergence in patients at risk for emergence delirium from ketamine?
Benzodiazepine
This induction agent has the highest analgesic properties.
Ketamine
Combining, admixing, diluting, pooling, reconsitutring, repackaging, or otherwise altering a drug or bulk drug substance to create a sterile preparation.
Sterile Compounding
The experience of pain with a series of complex neurophysiologic processes
Nociception
What are the two components of pain?
- Sensory-discriminative - preception
- Motivational-affective - response to pain
Increased pain sensations to normally painful stimuli
Hyperalgesia
Allodynia
Perception of pain sensations in response to normally non-painful stimuli
Nerve/electrical impulses/signals start at the nerve endings
Transduction
Travel of nerve/electrical impulses to the nerve body connecting to the the dorsal horn of the spinal cord.
Transmission
Process of altering (inhibitory/excitatory) pain transmission mechanisms at the dorsal horn to the PNS and CNS.
Modulation
Thalamus acting as the central relay station for incoming pain signals and the primary somatosensory coretex serving for discrimination of specfic stimuli
Preception
Where does the modulation of pain impulses occur?
Dorsal Horn
Chemical Mediators
PELNCCE
- Peptides (Substance P, Calcitonin, Bradykinin, CGRP)
- Eicosanoids
- Lipids (Prostaglandins, Thromboxanes, Leukotrienes, Endocannabinoids)
- Neutrophils
- Cytokines
- Chemokines
- Extracellular proteases and protons
At the original site of injury from heat and mechanical injury
Primary Hyperalgesia
Pain sensation from uninjured skin surrounding the actual injury (only from mechanical stimuli)
Secondary hyperalgesia
Pain is not felt with simultaneous inhibitory impulses
Gate Closed
A beta fibers
Pain is projected to supraspinal brain regions
Gate open
A delta & C fibers
Which lamina is the substantia gelatinosa? What affects this pathway?
Lamina II; Opiates and afferent C-fibers
Which lamina is the marginal layer? Which fibers use this pathway?
Lamina I; C-fibers
What lamina has the NKI receptor? What activates this receptor?
Lamina III & IV; Substance P
What structures depress or facilitate the integration of pain info in the spinal dorsal horn?
Periaqueductal gray-rostral ventromedial medulla (PAG-RVM)
What are the 5 excitatory impulses?
GCNAS
- Glutamate
- Calcitonin
- Neuropeptide Y
- Aspartate
- Substance P
What are the 5 inhibitory impulses?
GGEND
- GABA
- Glycine
- Enkephalins
- Norepinephrine
- Dopamine
What are the two descending pathways of pain modulation?
- Descending inhibition pathway
- Descending facilitation pathway
What are the 4 ascending pathways of nociceptive information?
- Spinothalamic - pain, temp, itch
- Spinomedullary
- Spinobulbar
- Spinohypothalamic - autonomic
When do neonates start to feel pain?
23 weeks of gestation
What are the receptors for the PAG-RVM system?
μ, κ, δ
What type of pain persists after the tissue has healed? Cancer patients have an increased risk for this type of pain.
Neuropathic
Will also see allodynia and hyperalgesia with this type pain.
What is the GI response to pain?
N/V
What are the emotional responses to pain?
- Anxiety
- Sleep disturbance
- Depression
What are the immune responses to pain?
- Leukocytosis- stress related
- Depressed reticuloendothelial system - increased infection
What are the 4 advantages of opioid agonist-antagonists?
- Analgesia
- Limited ventilation depression
- Low potential for physical dependence
- Ceiling effect prevents additional responses
When are opiod agnists-antagonists used?
When a patient is unable to tolerate a pure agonist
What is the MoA for opioid agonists-antagonists?
- μ - partial (agonist) or no effect (competitive antagonist)
- κ, δ - partial effect (agonist)
Which opiod agonist-antagonist has withdrawal as a side effect?
Burenorphine
Which opioid agonist-antagonist is used with cardiac catheterization patients?
Nalbuphine
Which opioid agonist-antagonist has effects on the κ, δ receptors with weak antagonist activity and excretion via glucoronide conjugates?
Pentazocine
Pentazocine
Butorphanol
Nalbuphrine
Buprenorphine
Nalorphine
Bremazocine
Dezocine
are all examples of what type of opioids?
Opioid agonists-antagonists
Which opioid agonist-antagonist is more potent than morphine?
Buprenorphine
Which opioid agonist-antagonist has affinity for all three opioid receptors?
Butorphanol
δ - minimal affinity
μ - low affinity
κ - moderate affinity
What are the 3 opioid antagonists?
Naloxone
Naltrexone
Nalmefene
What are two other uses for Naloxone?
- Neonate
- Antagonism of general anesthesia at high doses
How long does Naloxone last?
30 to 45 minutes
What is the MoA of opioid antagonists?
Pure μ opioid receptor competitive antagonists with no agonist activity.
Name three S/E of Naloxone.
- Reversal of analgesia (not a side effect…)
- N/V
- Increased SNS (HR, BP, pulmonary edema, arrythmias)
What kind of medications are suboxone, Embeda, and OxyNal?
Tamper or abuse resistant opioids
1. Suboxone (buprenorphine + naloxone)
2. Emebda (ER morphine + naltrexone)
3. OxyNal (oxycodone + naltrexone)
What medication decreases MAC? How much of a decrease?
Fentanyl; decreases MAC of Iso and Des by 50%
What structure/pathway in the spinal cord contains opioid receptors?
Substantia Gelatinosa
What are the neuraxial routes for opioids?
- Epidural
- Spinal
- Intrathecal
- Subarachnoid
What does adding epinephrine to epidurals help prevent?
Venous plexus injuries
What are the peak concentrations in epidurals for Fent, Sufent, and Morphine?
Sufent - 6 minutes
Fent - 20 mimnutes
Morphine - 1-4 hours
What causes itching with neuraxial opioids?
Cephalad (head or anterior end of the body) migration of the opioid to trigeminal nucleus
What determines cephalad movement of opioids in the CSF?
Lipid solubility
Which drug is used to attenuate the side effects of neuraxial opiods?
Naloxone
Which opiates are phenanthrenes?
- Morphine
- Codeine
- Thebaine
Greek word stupor, which has the potential to produce physical dependence
Narcotic
All exogenous substances (natural & synthetic)
Opioid
In addition to opiate receptors, where else do opiates have an effect?
Pre & postsynaptic sites in the CNS
Opiates have ____synaptic inhibition of what substances?
pre; ACh, dopa, NE, Substance P
Where are the opioid receptors in the brain?
- Periaqueductal gray (PAG)
- Locus ceruleus
- rostral ventral medulla (RVM)
- Hypothalamus
Where are the opioid receptors in the spinal cord?
Interneurons and primary afferent neurons in the dorsal horn (substantia gelatinosa)
Where are the opioid receptors outside of the CNS?
sensory neurons and immune cells
What is the CV benefit of opioids?
cardioprotective from myocardial ischemia
What is the primary CV side effect of opioids?
Decreased SNS tone in peripheral veins (decreases VR, CO, & BP, orthostatic hypotension & syncope), bradycardia
Which medication increases CNS levels of ACh and antagonizes ventilatory depression, but not analgesia?
Physostigmine
What is the MoA for decreased ventilation with opiates?
- Activation of Mu2 receptors which decrease ventilation rate with a compensatory increase in tidal volume
- Increased in resting PaCO2
What are symptoms of opioid overdose?
Hypoventilation, miosis apnea, & coma
What’s a contraindication for opiates?
Head injury
What are 3 CNS side effects of opioids?
- Myoclonus with large doses
- Thoracic and abdominal muscle rigidity
- Decreased CBF and possibly ICP
What 3 opiates cause spasm of biliary smooth muscle or sphincter of Oddi spasms?
- Fentantyl
- Morphine
- Meperidine
What medication is given for patients with biliary smooth muscle spasms?
Glucagon (2 mgs IV - given incrementally)
What is the primary GI side effect of opioids?
Delayed gastic emptying and constipation
What are the initial symptoms of opioid withdrawal?
Yawning, diaphoresis, lacrimation, insomnia, restlessness, coryza
What is the onset time for fentanyl, sufentantil, and remifentantil?
30-60 seconds
What are the two metabolites of morphone?
- Morphine-3-glucuronide (inactive)
- Morphine-6-glucuronide (active)
What type of pain is morphine best at?
dull pain
What is the normal dose for morphine?
1-10mg IV
What is the normal onset for morphine?
10-20 minutes
What is the peak time for morphine?
15-30 minutes
Which morphine metabolite has a longer elimination 1/2 time?
Morphine-3-Glucuronide
caution with renal dysfunction
Which receptors does meperidine work on?
Mu and kappa
What are the 4 analogues of mepridine?
- Fentanyl
- Sufentanil
- Alfentanil
- Remifentanil
What’s the dose for post-op shivering with meperidine?
12.5 mgs
What is the duration of meperidine? What is the elimiation 1/2 time?
2 to 4 hours; 3 to 5 hours
What is the induction dose of fentantyl?
1.5 to 3 mcg/kg IV
What is the analgesic dose of Fentanyl
1-2 mcg/kg IV
What’s the induction dose of remifentanil?
0.5 to 1 mcg/kg IV over 30-60 seconds
What is the maintainence dose of remifentanil?
0.005 to 2 mcg/kg/min
What can using alfentanil with alzheimer patients cause?
acute dystonia
What is the dose of hydromorphone?
0.5 mg IV (1 to 4 mgs total)
What is the cough suppressant dose of coedine?
15 mgs
What receptors does tramadol work on?
Mu, weak kappa, and delta.
What’s the chemical ring in most opioids?
Piperdine
What is the dose for super mag?
400 mg
What is the dose for IV tylenol?
1000mg q4-6 hours.
What is the intraop dosage for ibuprofen?
200-800 mg IV over 30 minutes Q6h
What are the chronic pain syndromes gabapentin can be used for?
- Diabetic neuropathy
- Post-herpetic neuralgia
- Reflex sympathetic dystrophy
- Phatom limb pain
- Fibromyalgia
What are the two primary indications for gabapentin?
- Partial seizures in adults/children
- chronic pain syndromes
What’s the MoA for gabapentin?
- Binds VG-Ca2+channels
- Enhances descending inhibition
- Inhibits excitatory NT release
What’s the dose for gabapentin?
300-1200mg PO 1-2 hours prior to OR
When is Gabapentin contraindiciated?
- MG
- Myoclonus
Reduce dose in elderly.
What are some of the benefits of NSAIDs?
- Long duration of action
- Prepemptive analgesia
- Less N/V
- Abscense of cognitive effects
- No addictive potential
- No respiratory depression
What do NSAIDs do?
- Analgesic (Decrease activation of peripheral nociceptors)
- Antiinflamatory
- Antipyretic
What medications are the nonspecific NSAIDs?
- Ibuprofen
- Naproxen
- Aspirin
- Acetaminophen
- Ketorolac
What are the COX-2 Selective NSAIDs?
- Celecoxib (Celebrex)
- Rofecoxib (Vioxx)
- Valdecoxib (Bextra)
- Parecoxib (Dynastat)
What’s the dose for Celebrex?
200 to 400mg PO QD
What is the enzyme that catalyzes synthesis of PG?
Cyclooyxgenase
Ubiquitous, “physiologic”, “Constituative”
COX-1
“Inducible”, “pathophysiologic”, sensitization
COX-2
What’s the dose for ketorolac?
15-30mg q6hr
1/2 dose in elderly
What is the peak for IV tylenol?
30 minutes to 1 hour
What is the TEAM health forumla for Ketamine?
- 0.25 to 0.5 mg/kg pre incision
- 0.25 to 0.5 mg/kg intraop
- Stop 1 hour prior to surgery end
- 0.12 mg/kg/hr for 24 hours postop
or 5mg boluses between 0.3 to 0.5 mg/kg/hr
What’s the dose for lidocaine?
1-2 mg/kg IV over 2-4 minutes
What’s the TEAM health dose for Lidocaine?
- 1.5 mg/kg at induction
- 1-2 mg/kg/hr for 24 to 48 hours post-op
What dose of lidocaine corresponds to analgesia?
1-5 mcg/mL
What dose of lidocaine corresponds to tinnitus, muscle twitching, hypotension, myocardial depression, and oral numbness
5-10 mcg/mL
What dose of lidocaine corresonds to seizures and unconciousness?
10-15 mcg / mL
What dose of lidocaine corresponse to apnea and coma?
15-25 mcg/mL
What dose of lidocaine corresponds to cardiovascular depression?
> 25 mcg/mL
What is the primary contraindication for Ketorolac (Toradol)?
Severe renal impairment
What’s the peak time for celebrex?
3 hours
What’s the team health dose of Mg2+
30 to 50 mg/kg IV loading dose
Continue 8 to 10 mg/kg/hr
What’s the preop dose for Mg2+
50 mg/kg IV
What decreases ondansetron effectiveness?
Variations in CYP2D6 activity
What’s the dose for ondansetron?
4 mg to 8mg IV
What’s the dose for pediatric ondansetron?
0.1 mg/kg IV
What medications do corticosteroids increase the effectiveness of?
Increases effectiveness for 5-HT3 antagonists and droperidol
What is the dose for decadron?
8 to 10 mgs?
What endogenous substances are peptides?
SCBC
Substance P, Calcitonin, Bradykinin, and CGRP
What endogenous substances are lipids?
PTLE
Prostaglandins, Thromboxanes, Leukotrienes, and Endocannabinoids