Famotidine — Histamine-2 (H2) receptor antagonist. Study the mechanism, listed uses and warnings from the US label on one sourced card.
Generic name
Famotidine
Class
Histamine-2 (H2) receptor antagonist
Mechanism
Competitive inhibitor of histamine-2 receptors; suppresses both acid concentration and volume of gastric secretion.
Used for
Active duodenal or gastric ulcer, nonerosive GERD, or erosive esophagitis in adults and children weighing at least 40 kg; Pathological acid-hypersecretory conditions in adults; Reduction of duodenal-ulcer recurrence risk in adults
Common side effects
Headache; Dizziness; Constipation; Diarrhea
Warnings
CNS adverse reactions (elderly, renal impairment); GI malignancy may be masked
Interactions
Medicines requiring gastric acidity for absorption; Tizanidine: potential increased exposure and hypotension, bradycardia or drowsiness; the source notes that this interaction has not been studied clinically
Brand questions use only name pairings verified against the linked product source. Unverified pairings are withheld from these questions; the other study content remains available.
Label date: 20260820 · For learning, not clinical decisions. US label and brand information; always consult the current source.
Source snapshot checked: 2026-10-21. The source document and selected fields were compared. The complete card has not had an independent clinical review.
Mechanism: Selective 5-HT3 receptor antagonist; 5-HT3 receptors are on vagal nerve terminals and in the chemoreceptor trigger zone.
On both cards: Common side effects — Headache; Constipation; Diarrhea
Only on the Ondansetron card: Used for — Prevention of chemotherapy-associated nausea and vomiting in adults; pediatric use from age 4 years is established only for moderately emetogenic chemotherapy; Prevention of nausea and vomiting from the specified radiotherapy regimens in adults; Prevention of postoperative nausea and vomiting in adults · Common side effects — Malaise / fatigue · Warnings — Hypersensitivity incl. anaphylaxis; QT prolongation / torsade de pointes; Serotonin syndrome · Interactions — Apomorphine; Serotonergic drugs (SSRIs, SNRIs)
Mechanism: Substituted benzimidazole that inhibits the H+/K+ ATPase (proton pump) of the gastric parietal cell, blocking the final step of acid secretion.
On both cards: Common side effects — Headache; Diarrhea
Only on the Omeprazole card: Used for — Short-term treatment of active duodenal or benign gastric ulcer in adults; H. pylori eradication with the specified antibiotics in adults with duodenal ulcer disease; Short-term symptomatic GERD or erosive esophagitis treatment, and maintenance of healed erosive esophagitis, in patients aged 2 years and older; Long-term treatment of pathological hypersecretory conditions in adults · Common side effects — Abdominal pain; Nausea; Flatulence · Warnings — Acute tubulointerstitial nephritis; C. difficile-associated diarrhea; Bone fracture with long-term use · Interactions — Clopidogrel; Rilpivirine, atazanavir, nelfinavir; Warfarin
Mechanism: Covalently binds the H+/K+ ATPase of the gastric parietal cell, suppressing the final step of acid production, basal and stimulated.
On both cards: Common side effects — Headache; Diarrhea
Only on the Pantoprazole card: Used for — Short-term healing and symptom relief of GERD-associated erosive esophagitis in adults and children aged 5 years and older; Maintenance of healed erosive esophagitis and reduction of heartburn relapse in adults with GERD; Long-term treatment of pathological hypersecretory conditions, including Zollinger-Ellison syndrome, in adults · Common side effects — Nausea; Abdominal pain · Warnings — C. difficile-associated diarrhea; Bone fracture with long-term use; Vitamin B12 deficiency · Interactions — Rilpivirine-containing antiretrovirals; Warfarin; Methotrexate
An item counts as shared only when both cards use the same wording. If a card does not list an item, that is not a statement that the effect never occurs.
Capsera