Antiemetic/PONV Prophylaxis Drugs Flashcards
Diphenhydramine (Benadryl)
MOA
Receptor
H1
MOA
Vestibular system; airway SM; cardiac endothelial cells
Diphenhydramine (Benadryl)
Dosing
IV: 25-50 mg
Diphenhydramine (Benadryl)
Onset
Peak
Half-life
Onset
Rapid
Peak
2 hrs
Half-life
7-12 hrs
Diphenhydramine (Benadryl)
Side Effects
&
Considerations
Sedation/drowsiness
Stimulates ventilation
Anticholinergic effects;
blurred vision, urinary retention,
dry mouth
Anti-emetic rescue
Anti-pyretic;
allergic response treatment
May have anti-emetic properties d/t inhibiting the oculo-emetic reflex
Promethazine (Phenergan)
MOA
Receptor
H1
MOA
Vestibular system; airway SM; cardiac endothelial cells
Class - Phenothiazine
Promethazine (Phenergan)
Onset
Half-life
Onset
5 min
Half-life
9-16 hrs
Promethazine (Phenergan)
Side Effects
&
Considerations
Anticholinergic effects;
blurred vision, urinary retention, dry mouth
Sedation/drowsiness;
Local site extravasation (Age <2); respiratory depression
Anti-emetic rescue
Reduces peripheral pain levels d/t anti-inflammatory effects
Metoclopramide (Reglan)
Drug Class
&
MOA
Drug Class
Dopamine Antagonist
MOA
Blocks D1 & ↑ doses block 5HT3 in CTZ in CNS; enhances Ach in ↑GI tract to increase motility
Metoclopramide (Reglan)
Dosing
IV: 10-20 mg
over 3-5 min
Metoclopramide (Reglan)
Onset
IV: 15-30 min
Metoclopramide (Reglan)
Side Effects
&
Considerations
Abd. cramping (rapid IV); muscle spasms; ↓BP; ↑prolactin release
Neuroleptic
Malignant Syndrome: ↑temp, muscle rigidity, ↑HR, confusion
↓ Cholinesterase levels: slows metabolism of succinylcholine, mivacurium, ester LA
Only drug FDA-approved for DM gastroparesis
Droperidol (Inapsine)
Drug Class
&
MOA
Drug class
Butyrophenones
MOA
Dopamine anatagonist
Blocks D2 in CTZ in CNS
Droperidol (Inapsine)
Dosing
IV: 0.625-1.25 mg
Anti-emetic
Droperidol (Inapsine)
Side Effects
&
Considerations
Extrapyramidal symptoms
Prolonged QTc intervals/torsades
in higher doses
More effective than metoclomapride & equally effective to 4 mg ondansetron
Avoid in other CNS depressants: barbituates, opioids, GA
Neuroleptic
Malignant Syndrome:
↑temp, muscle rigidity,
↑HR, confusion
Black box warning;
drug interactions to
amiodarone, diuretics, sotalol, mineralcorticoids, CCB
Ondansetron (Zofran)
Drug Class
&
MOA
Drug Class
5HT3 antagonist
MOA
Blocks 5HT3 PNS on vagal nerve terminals & CTZ in CNS
Ondansetron (Zofran)
Dosing
IV: 4-8 mg
Ondansetron (Zofran)
Onset
Peak
Duration
Half-life
Onset
Rapid
Peak
15-30 min
Duration
4 hrs
Half-life
4 hrs
Ondansetron (Zofran)
Side Effects
&
Considerations
HA; diarrhea
Slight QTc prolongation
Can be given prior to
neuraxial anesthesia
to prophylactically
treat hypotension
Dexamethosane (Decadron)
Drug Class
&
MOA
Drug Class
Corticosteriod
MOA
Anti-inflammatory by
neutrophil suppression,
↓inflammatory mediators &
reverses capillary permeability;
antiemetic MOA unknown
Dexamethasone (Decadron)
Dosing
Anti-emetic
IV: 4-8 mg
Inflammation
IV: 12-16 mg
Dexamethasone (Decadron)
Onset
Peak
Duration
Half-life
Onset
Rapid
Peak
5-10 min
Duration
Short
Half-life
1-5 hrs
Dexamethoson (Decadron)
Side Effects
&
Considerations
↑ BG; may not be clinicaly relevant;
perineal burning/itching
Increase effectiveness for
5HT3 antagonists & droperidol
Anti-inflammatory may result in
less post-op pain
Scopolamine
Drug Class
&
MOA
Drug Class
Anti-Ach;
muscarinic antagonist
MOA
Blocks Ach at parasympathetic sites in smooth muscle, secretory glands, & CNS
Scopolamine
Dosing
Topical: 1 Patch
140 mcg priming dose;
1.5 mg over 72 hrs
Scopolamine
Onset
Peak
Duration
Onset
4 hrs
Peak
8-24 hrs
Duration
24-72 hrs
Scopolamine
Side Effects
&
Considerations
Mydriasis;
Sedation;
Crosses BBB
*Apply 4 hrs prior to Sx
