Ondansetron (Zofran) dose, onset, peak, duration?
dose: 4 mg
onset: 30 minutes (i think)
peak: 2 hours
duration: 4 - 24 hours
Ondansetron (Zofran) mechanism of action?
- 5-HT3 receptor antagonist or serotonin antagonist
- binds to ligand-gated ion channels in GI tract and the brain, preventing binding of serotonin and the vagal effects that result from stimulation of vomit reflex
How is ondansetron (Zofran) metabolized and eliminated?
When is ondansetron (Zofran) contraindicated?
with decreased GI motility or decreased lower esophageal sphincter tone
Droperidol (Inapsine) dose, onset, peak, duration?
dose: 0.625 - 2.5 mg
onset: 1 - 2 minutes
peak: 30 minutes
duration: 2 - 4 hours
Droperidol (Inapsine) mechanism of action?
- dopamine-2 (D2) receptor antagonist
- inhibits D2 receptors in chemoreceptor trigger zone
Effects of droperidol (Inapsine) on the body? (and random facts…)
- prolongs QT interval => torsades de pointes
- decreases BP (d/t decreases in alpha adrenergic blockade)
- anti-dysrhythmic (0.2 - 0.6 mg/kg for tachydysrhythmias in WPW)
How is droperidol (Inapsine) metabolized and eliminated?
What are zofran and droperidol categorized as?
both are antiemetics
zofran - serotonin antagonist
droperidol - dopamine antagonist
Diphenhydramine (Benadryl) dose and duration?
dose: 50 mg
duration: 3 - 6 hours
(no onset or peak)
Diphenhydramine (Benadryl) mechanism of action?
- H1 antagonist
- selectively antagonizes H1 receptors, blocking histamine activation of gastric parietal cell proton pump
Effects of diphenhydramine on the body? (and random facts…)
pulmonary - may provide some protection against bronchospasm and opioid induced ventilatory depression (secondary to CO2 response depression)
cardiac - tachycardia is common
neuro - somnolence; impaired cognition
other - dry mouth, blurred vision, urinary retention.
beneficial for PONV and motion sickness/inner ear symptoms
Diphenhydramine (Benadryl) is categorized as?
a sedative, antipuretic, antiemetic, and as treatment of anaphylaxis
Ranitidine (Zantac) dose, peak, and duration?
dose: 2 - 4 mg/kg
peak: 1 - 3 hours
duration: 1.5 - 2.5 hours
(no onset time)
Ranitidine (Zantac) mechanism of action?
- H2 antagonist; proton pump inhibitor
- selectively antagonizes H2 receptors, blocking histamine activation of gastric parietal cell proton pump
Effects of ranitidine (Zantac) on the body?
cardiac - rare dysrhythmias (bradycardia, heart block, or hypotension)
neuro - rare mental confusion
other - *minimal CYP-450 interactions; *all side effects are rare
Should the ranitidine dose be increased or decreased with advancing age and/or renal dysfunction?
decrease the dose
How is ranitidine metabolized and eliminated?
How is diphenhydramine metabolized and eliminated?
Omeprazole (Prilosec) dose, onset, peak, duration?
dose: 20 mg PO
onset: 2 - 6 hours
peak: 2 - 4 hours (strange, i know)
duration: > 24 hours
Omeprazole (Prilosec) mechanism of action?
- proton pump inhibitor
- directly inhibits the H+/K+ ATP-ase proton pump, leading to an increase in gastric pH and a decrease in fluid volume
Effects of omeprazole (Prilosec) on the body? (and random facts…)
neuro - may cause headache, agitation, or confusion
other - *should be administered > 3 hours prior to induction; some GI side effects may be seen; no renal or hepatic dosing is necessary
How is omeprazole metabolized?
Metoclopramide (Reglan) dose, onset, peak, duration?
dose: 10 - 20 mg, given over 3 -5 minutes
onset: 1 - 3 minutes
peak: 5 minutes
duration: 1 - 2 hours
Metoclopramide (Reglan) mechanism of action?
- GI prokinetic
- dopamine-2 (D2) receptor antagonist; produces selective cholinergic stimulation of GI tract by:
1) increasing SM tone in lower esophageal sphincter and stomach
2) increasing gastric and small intestine motility
3) relaxes pylorus and duodenum when stomach contracts
How is metoclopramide (Reglan) metabolized and eliminated?
Effects of metoclopramine on the body? (and random facts…)
neuro - extra-pyramidal effects if on anti-psychotics; *avoid if history of seizures
other - *DO NOT GIVE if GI symptoms; *increases lower esophageal sphincter tone and GI motility; *speeds gastric emptying; *antiemetic action; *decreases gastric fluid volume
- inhibits plasma cholinesterase activity; opioid induced GI stasis and N/V is blunted by this drug