Centrally acting antiemetics Flashcards
Phenothiazines MEDS and prototype
chlorpromazine
perphenazine
prochlorperazine (Compro)
Promethazine
PROTOTYPE: Prochlorperazine
MOA and Indications of phenothiazines
MOA:
Change responsiveness/stimulation of CTZ in medulla
Most as dopamine antagonists
Promethazine is H2 receptor blocker
Indications:
Nausea and vomiting
Intractable hiccoughs
CI to phenothiazines
- Coma / CNS depression / TBI: Further CNS depression
- HTN/hypotension
- Liver dysfunction: Interfere with metabolism of drug
- Pregnancy / Lactation
- Pediatrics: Adverse effects on fetus
- *promethazine c/I < 2 y/o d/t respiratory depression
AE of phenothiazines
- CNS : drowsiness, dizziness, weakness, tremor, h/a
- Cardiac :hypotension, arrhythmia
- GI : dry mouth, nasal congestion, anorexia, pallor, sweating
- GU : urinary retention
DDI to phenothiazines
CNS depressants, antihypertensives: Additive cns depression and hypotension with cns depressants and antihypertensives
Extra symptoms to Prochlorperazine
Dystonia, photophobia, urine discoloration pink to red-brown
Non- phenothiazine MED
metoclopramide (Reglan)
MOA and indications of non-phenothiazine
MOA:
- Blocks dopamine receptors, making GI cells more sensitive to acetylcholine
- Increased GI activity/movement
Indications:
- Nausea and vomiting
- GERD
- Diabetic gastroparesis
- Promotion of GI movement w/SBO
- Promotion of rapid movement of barium
AE of non phenothiazines
- CNS – drowsiness, fatigue, restlessness, EPS, Parkinson-like rx, sz
- GI – n/d
- CNS depression
- Interfere with metabolism of drug
- Adverse effects on fetus *promethazine c/I < 2 y/o d/t respiratory depression
5 HT3 receptor blockers MEDS and prototype
Suffix: -tron
MEDS: granisetron (Sustol), ondansetron (Zofran), palonosetron
PROTOTYPE: Ondansetron
CI to 5HT3 receptors
- Abd surgery (masking signs of progressive ileus)
- Pregnancy / lactation: effects on fetus
- Long QT syndrome : Ondansetron will prolong T and electrolyte abn increase risk of torsades de pointes
- Electrolyte abn*
AE and DDI to 5HT3
AE:
CNS – myalgia, dizziness, h/a
GI – d/c
GU – urinary retention
DDI:
Serotonergic medications
QT prolonging medications (ventricular arrhythmias)
Substance P/neurokinin 1 receptor antagonist MEDS and prototype
MEDS: aprepitant and fosaprepitant dimeglumine (Cinvanti, Emend), rolapitant (Varubi)
PROTOTYPE: Aprepitant
MOA and indications of Substance P/neurokinin 1 receptor antagonist
MOA:
Act directly in CNS to block receptors associated with n/v
Little serotonin, dopamine or steroid receptor activation
Indications:
n/v associated with chemotherapy
AE and DDI of Substance P/neurokinin 1 receptor antagonist
AE:
GI : n/d/c, gastritis, anorexia
CNS : h/a, fatigue
Immune : neutropenia, anemia, leukopenia
DDI: warfarin, oral contraceptives
Miscellaneous Agents MEDS and prototype
MEDS:
dexamethasone (Decadron)
dimenhydrinate (Dramamine)
dronabinol (Marinol)
hydroxyzine (Vistaril)
meclizine (Antivert)
scopolamine (Transderm Scop)
trimethobenzamide (Tigan)
PROTOTYPE: Meclizine (end w/ -zine)
- urinary frequency
MOA, Indications, and CI to misc agents
MOA: various
Indications:
Nausea and vomiting
n/v associated with motion sickness
CI: varies
AE of misc agents
- Dimenhydrinate, hydroxyzine, meclizine : sedation, anticholinergic effects (no liquid to throw up)
- Dronabinol and nabilone :controlled substances : altered mental and physical states
- Scopolamine : anticholinergic effects, sedation
