52. Antiemetic and Antinausea Drugs

Question 1

Antiemetic drugs action

Answer 1

block vomiting pathways by blocking neurogenic stimulus; many block receptors in the CTZ

Question 2

Antihistamines (meclizine [Antivert], dimenhydrinate, diphenhydramine)

Answer 2

meclizine used to treat symptoms associated w motion sickness; contras shock & lactation

Question 2

Anticholinergics (scopolamine)

Answer 2

used for treatment and prevention of motion sickness; 72-hour transdermal patch, releases 1 mg total

Question 3

Antidopaminergics (prochlorperazine [Compazine], promethazine [Phenergan])

Answer 3

prochlorperazine injectable form used in hospital setting; promethazine not to be given intraarterially! will cause severe tissue damage

Question 4

Neurokinin Receptor Antagonists (aprepitant, [IV form is fosaprepitant])

Answer 4

aprepitant inhibits cytochrome P-450; fosaprepitant indicated as antiemetic in chemotherapy

Question 5

Prokinetic drugs (metoclopramide [Reglan])

Answer 5

increase GI motility; metoclopramide used for gastric emptying, GERD, and is available parenterally

Question 6

Serotonin blockers (ondansetron [Zofran], other -setrons) given 30-60 mins before chemotherapy or 30 mins before end of a surgery

Answer 6

prevention of nausea, vomiting, associated w chemotherapy or radiation. used in cancer and surgery; risk of QT widening

Question 7

Tetrahydrocannabinoid (dronabinol [Marinol])

Answer 7

dronabinol only commercially available tetrahydrocannabinoid; stimulates appetite and weight gain in AIDS and chemo pts

Question 8

Misc. antinausea drug (phosphorylated carbohydrate solution)

Answer 8

reduces cramping, used in mild nausea and vomiting, unlabeled use for morning sickness; not used for severe nausea symptom

Question 9

Ginger interaction w anticoagulants (Warfarin)

Answer 9

Increased bleed risk interaction