Lecture 4 Pre-op Medication Test 1 Flashcards
Histamines are endogenous substances that are released from ___________ and _______________.
Basophils; Mast Cells
What does histamine do to the airway?
What does histamine do in the stomach?
Histamine causes what NTs to be released in the CNS?
Contraction of smooth muscles in the airway.
Acid Secretions in the stomach.
Histamine will cause the release of serotonin, acetylcholine, and norepinephrine in the CNS.
What drugs will induce histamine release?
Morphine
Protamine
Mivacurium
Atracurium
When H1 histamine receptors are activated it can activate ______, _________, __________, and ________ receptors.
Muscarinic
Cholinergic
5HT3
Alpha-adrenergic
When H2 histamine receptors are activated, it can activate ________ and ________ receptors.
5HT3
Beta-1
When histamine binds to an H1-receptor what will be the result?
Hyperalgesia and inflammatory pain (insect sting)
Allergic rhino-conjunctivitis symptoms
When histamine binds to an H2-receptor what will be the result?
Elevate cAMP (Beta1-like stimulation, tachycardia)
Increase acid and volume production
Activation of both H1 and H2 receptors will result in what symptoms?
Prostacyclin Release
Capillary permeability
Tachycardia
Hypotension d/t release of NO
Flushing
What is the most accurate description of an antihistamine?
Inverse Agonist
They don’t prevent the release of histamine but responses
What are the effects of H1 receptor antagonists on the following areas?
Vestibular System:
Airway Smooth Muscle:
Cardiac Endothelial:
What are the effects of H1 receptor antagonists on the following areas?
Vestibular System: Effective for motion sickness
Airway Smooth Muscle: protection against bronchospasms
Cardiac Endothelial: provide cardiac stability
The first-generation H1 antagonist causes a lot of ____________ as a side effect.
sedation
Can you develop tachyphylaxis from H1 receptors?
No
What are the side effects of H1 receptor antagonists?
Blurred Vision
Urinary Retention
Dry Mouth
Drowsiness/Sedation (first gen)
What are examples of H1 receptor antagonist drugs?
Diphenhydramine (Benadryl)
Promethazine (Phenergan)
Cetirizine (Zyrtec)
Loratadine (Claritin)
This H1 receptor drug is mostly used as an antipruritic and pre-treat procedure-related allergy (IVP dye)
Benadryl
Diphenhydramine inhibits the afferent arc of the ________________.
Oculo-emetic reflex
Diphenhydramine can stimulate ventilation by augmenting the relationship of ____________ and ___________ drive.
Hypoxic, Hypercarbic
Only if given as a solo administration
What is the IV dose of Benadryl?
What is the half-time of Benadryl?
25-50mg IV
7-12 hours
Which H1 receptor antagonist is a great anti-emetic and is used as a rescue and reduces peripheral pain levels (anti-inflammatory effects).
Promethazine
What is the IV dose of Promethazine?
How long does it take to onset?
What is the half-time of Promethazine?
12.5-25mg IV (give less to the elderly)
5 minutes for onset
9-16 hours
What were the black box warnings for Phenergan?
Can cause death in children under the age of 2.
Can cause extravasation and ischemia to the tissue from IV injection.
H2 receptors antagonist are most commonly used in __________.
How does an H2 receptor antagonist work?
Duodenal ulcer disease / GERD
Decrease hypersecretion of gastric fluid (H+) from gastric parietal cells and decrease cAMP, which will decrease gastric volume and increase pH.
H2 receptor antagonist can increase serum creatine by _______% d/t competition for tubular secretion.
15%
What are the side effects of H2 receptor antagonists?
HA/Confusion (Elderly)
Bradycardia
Diarrhea
Skeletal Muscle Pain
Weakened Gastric Mucosa
Creatine Increase
Overgrowth of ____________ can increase pulmonary infections d/t weakened gastric mucosa from prolonged administration of H2 antagonist.
Candida Albicans
What are examples of H2 receptor antagonists?
Cimetidine (Tagamet)
Ranitidine (Zantac)
Famotidine (Pepcid)
How is Cimetidine metabolized?
CYP450, hepatic metabolism, renal clearance
Cimetidine strongly inhibits CYP 450 and can affect the metabolism of which drugs?
Warfarin
Phenytoin
Lidocaine
Tricyclics
Propranolol (Inderal)
Nifedipine
MEperidine
Diazepam
What are the adverse effects of Cimetidine?
Bradycardia
Hypotension (rapid infusion)
Increase Prolactin
Impotence (Inhibits dihydrotestosterone binding to androgen receptors)
What is the dose of cimetidine?
What about renal dosing?
150-300mg IV
75-150mg IV
How is Ranitine metabolized?
CYP450, hepatic metabolism, renal clearance
What is the dose of Ranitidine?
What about renal dosing?
50mg diluted to 20cc given over 2 minutes.
25mg diluted to 20cc given over 2 minutes.
How is Famotidine metabolized?
CYP450, hepatic metabolism, renal clearance
What interference is Famotidine involved with?
Interferes with phosphate absorption and can result in phosphatemia.
Bone fractures or hips hurting
What is the dosing for famotidine?
What about renal dosing?
What is the half-time for famotidine?
20mg IV
10mg IV
2.5-4 hours (most potent and longest of all H2 receptor antagonist)
What group of drugs irreversibly bind to acid secretion pumps and inhibit the movement of protons (H+) across the gastric parietal cells?
Proton Pump Inhibitors
How many days does it take for the onset of PPIs?
3 to 5 days
What are PPIs most effective against?
Controlling gastric acidity
Decreasing Volume
PPIs are more effective than H2 receptors in what 4 areas?
Healing esophagitis
Healing ulcers
Relieving symptoms of GERD
Best treatment of Zollinger-Ellison Syndrome
What are examples of PPI?
Omeprazole (Prilosec)
Pantoprazole (Protonix)
Lansoprazole (Prevacid)
Dexlansoprazole (Dexilent)
What have PPIs been associated with?
Bone Fractures
SLE
Acute Intestinal Nephritis
C-diff
Vitamin B12
Magnesium Deficiency
PPI will inhibit ____________ metabolism.
PPI will block enzymes that activate ____________.
Warfarin (Warfarin can work too well with PPI, watch the INR)
Clopidogrel (Clopidogrel won’t work as well with PPI)
Omeprazole is enteric coated and is a prodrug that protonates in the _____________ to its active form.
Omeprazole only inhibit pumps that are present, acid inhibition increases with repeated dosing, but it only covers about ___________% maximum inhibition.
Parietal Cells
66%
How is omeprazole metabolized?
CYP metabolism
What is the dosing of omeprazole?
If given PO, how long before surgery?
40mg in 100cc NS given over 30 minutes
PO, at least 3 hours prior to surgery
What are the side effects of omeprazole?
HA (crosses BBB)
Agitation (crosses BBB)
Confusion (crosses BBB)
Abdominal Pain
N/V
Flatulence
SB bacterial overgrowth
How is Protonix metabolized?
Protonix has a greater _____________ and longer ___________ compared to omeprazole.
CYP metabolism
Greater bioavailability, and greater half time
What is the dose of Protonix?
How long before surgery can you give Protonix?
40mg in 100cc given over 2-15 minutes
1 hour before to decrease gastric volume and increase pH (works as fast as ranitidine)
PPI’s are the treatment of choice for ______, _______, and _______.
GERD
Gastroduodenal Ulcers
Acute upper GI Hemorrhage (post EGD treatment)
What is given to treat NSAID ulceration?
Omeprazole
What will protect the acidity of aspiration pneumonitis and be the most cost-effective for intermittent symptoms?
H2 antagonist
What is a particulate antacid?
What is a non-particulate antacid?
Particulate antacids are Aluminum or Magnesium based. Aspiration equals acid aspiration.
Non-Particulate antacids are Sodium, Carbonate, Citrate, or Bicarb base. Neutralize Acid.
What are long-term effects of all antacids?
If pH is too high, acid breakdown of food will be inhibited and acid rebound can occur.
What are the long-term effects of magnesium-based antacids?
What are the long-term effects of calcium-based antacids?
What are the long-term effects of sodium-based antacids?
Magnesium-based: Osmotic diarrhea, neurological/neuromuscular impairment
Calcium-based: Hypercalcemia, Kidney stones
Sodium-based: Hypertension
How does sodium citrate (Bicitra) neutralizes acid?
The Bicitra and acid are combined to make salt, CO2, and water, resulting in neutralization.
Sodium citrate increases __________.
Intra-gastric volume
What is the dose of sodium citrate?
When does it lose its effectiveness?
15-30 mL
After 30-60 minutes
Pregnancies are considered full stomach after _________ weeks.
12 weeks
What types of drugs are known for stimulating gastric motility (prokinetic)?
These drugs will increase lower esophageal _____________.
Stimulate _______________.
Relax ____________ and ____________ for the gastric emptying of intestinal transit.
Dopamine-blocking drugs for full stomachs
Lower Esophageal Sphincter tone.
Stimulate Peristalsis.
Relax Pylorus and Duodeum.
Who is contraindicated by dopamine blockers?
Individuals who are dopamine depleted (Parkinson’s).
What are the side effects of dopamine blockers?
Extrapyramidal reactions (easily crosses BBB)
Orthostatic Hypotension
Can affect the chemoreceptor trigger zone (antiemetic effect).
No change in gastric pH
What are examples of dopamine blockers?
Metoclopramide (Reglan)
Domperidone - not available in the US
Droperidol (Inapsine)
What is the FDA-cleared drug for diabetic gastroparesis?
Metoclopramide (Reglan)
What are the side effects of Reglan?
Abdominal cramps from the rapid infusion
Muscle Spasm
Hypotension
Sedation
Increase Prolactin Release
Neuroleptic malignant syndrome
Decrease plasma cholinesterase levels - slow metabolism of succinylcholine, mivacurium, and ester local anesthetics.
What is the dose of Reglan?
When do give before induction?
10-20mg given over 3 to 5 minutes
15 to 30 minutes before induction
Unlike Reglan, _____________ does not cross the BBB and has no anticholinergic activity.
It also increases __________ secretion by the pituitary to a greater degree.
This is not FDA-approved due to _________ and __________ but is available outside the country.
Domperidone
Prolactin
Dysrhythmias and Sudden Death
What drug was initially developed for schizophrenia and psychosis?
Like Reglan, this drug can cause __________and __________ as adverse side effects.
Droperidol (Inapsine)
Extrapyramidal syndrome and Neuroleptic Malignant Syndrome
What CNS depressants do you want to avoid with droperidol?
Barbituates
Opioids
General Anesthesia (lol)
Droperidol is more effective than ______________ for N/V.
Droperidol is equally effective to ____ mg of ____________ for N/V.
Reglan
4 mg of Zofran
What is the black box warning for Droperidol?
Prolonged QT intervals
Torsades with higher doses
Serious Drug Interactions: Amio, Diuretics, Beta Blockers, CCB, Steroids
What is the dose for droperidol?
0.625 to 1.25mg IV
____________ is released from the chromaffin cells of the small intestine and stimulates _______________ through 5HT3 receptors that cause __________.
Serotonin
Vagal Afferents
Vomiting
Serotonin 5HT3 receptors are ubiquitous they are in the kidneys, lungs, colon, liver, and stomach. There is a large concentration of 5HT3 receptors in the ________ and __________.
Brain and GI Tract
What group of drug that was originally used in chemo and radiation therapy related to N/V is now used for PONV? It is a competitive antagonist with almost no side effects.
5HT3 antagonist
What is 5HT3 not effective against?
Motion sickness and vestibular stimulation
What are examples of 5HT3 antagonists?
Ondansetron (Zofran)
Granisetron (Kytril)
Dolasetron (Anzemet)
Which drug is the first 5HT3 antagonist and does not cross the BBB.
Ondansetron (Zofran)
What are the side effects of Zofran?
HA
Diarrhea
Slight QT prolongation
What is the dose of Zofran?
What is the plasma half-life?
4 or 8mg IV
4 hours (Give Zofran at the end of the case)
The exact mechanism of this group of drug is unknown for N/V, but it centrally inhibits prostaglandin synthesis and control endorphin release.
There is also increased effectiveness for 5HT3 antagonist and droperidol.
This group of drugs also has an anti-inflammatory effect resulting in less post-op pain, and less opioid use.
Corticosteroids
What is the diabetic risk of Decadron?
What is another side effect of Decadron?
Perioperative Hyperglycemia (minimal side effect with one dose)
Perineal Burning/Itching (rapid IV push)
What is the dose of Decadron?
What is the delay in onset?
How long does the efficacy of decadron persist?
4mg or 8mg
2 hours (Give Decadron at the beginning of the case)
24 hours
When will you consider giving an increased dose of decadron?
Airway trauma d/t multiple intubation attempts (12 or 16 mg)
What are Scopolamine patches used for?
They are muscarinic antagonists (anticholinergic) for nausea and vomiting.
They have both central and peripheral effects (crosses the BBB, sedation)
What are the side effects of Scopolamine patches?
Dilated pupils
Sedation
Peak concentration hours for Scopolamine patches are between _________ and __________ hours.
How long does it take the patch to work?
8 to 24 hours
4 hours for onset of action.
What is the priming dose of Scopolamine?
How much scopolamine will be given over the next 72 hours?
Where will the patch be placed?
140 mcg
1.5mg
Post-auricular
What group of drugs is similar to epinephrine that stimulates the G-proteins, activates cAMP which will decrease Ca2+ entry, and relax smooth muscles in the airway?
Beta-receptor agonists (Bronchodilators)
Bronchodilators can reduce inflammatory cell activation, directly relax smooth muscles, and increase FEV1 by _________% within ______ minutes (2 puffs).
15% improvement in 6 minutes
How do you deliver an inhaled SABA?
Discharge inhaler while taking a slow deep breath over 5-6 seconds.
Hold your breath at max inspiration for 5-6 seconds.
What percentage of the inhaled SABA reaches the lungs?
What percentage of the inhaled SABA is delivered to the lungs through mechanical ventilation?
How often are inhaled SABAs given?
12%
50-70%
Every 4 hours
What are the side effects of beta agonists?
Tremor
Tachycardia
Transient Decrease in arterial oxygenation
Hyperglycemia
What are examples of bronchodilators?
Albuterol (Proventil)
Levo-albuterol (Xopenex)
What are ways to deliver SABA?
- Inhaler
- Puff piece nebulizer
- Syringe