Digestive / GI

Drugs that manage acid, nausea, and elimination throughout the gastrointestinal tract. The recurring themes: suppress acid at the right point in the parietal cell, block the serotonin trigger that drives vomiting, and never push the bowel forward before ruling out an obstruction.

8 drug classes 34 key drugs

Proton Pump Inhibitors

-prazole High-yield

Irreversibly shut off the stomach’s acid pump — the most powerful acid suppressors. Take before the first meal; think about long-term effects and the clopidogrel interaction.

Antiemetics

-setron High-yield

Block the serotonin (5-HT3) trigger that drives vomiting from chemo, radiation, and surgery. The must-know risk is ondansetron’s dose-dependent QT prolongation.

H2 Antagonists

-tidine High-yield

Block the histamine (H2) arm of acid secretion — milder and faster than PPIs but shorter-acting and prone to tolerance. Famotidine is now the mainstay; cimetidine has many interactions.

Laxatives

High-yield

Promote elimination by several distinct mechanisms. The universal nursing rule: rule out bowel obstruction before giving any laxative.

Antacids

Neutralize stomach acid for fast, short heartburn relief. Separate from other drugs; mind the bowel effects.

Antidiarrheals

Slow the gut to control diarrhea — but rule out infection first. High-dose loperamide is cardiotoxic.

5-ASA / IBD Agents

Locally acting anti-inflammatories that induce and maintain remission in inflammatory bowel disease. Sulfasalazine’s sulfa half drives its side effects.

GI Antispasmodics

Anticholinergics that relax gut smooth muscle to ease cramping in IBS. The whole side-effect profile is anticholinergic — "can’t see, spit, pee, or poop."