Famotidine
Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.
| ID | DRUG-FAMOTIDINE |
|---|---|
| Type | Drug |
| Aliases | KvamatelPepcidQuamatelФамотидин |
| Status | reviewed 2026-04-27 | pending_clinical_signoff |
| Diseases | None declared |
| Sources | SRC-NCCN-BCELL-2025 SRC-NCCN-MM-2025 |
Drug Facts
| Class | Histamine H2 receptor antagonist (acid suppression; allergic-reaction H2 blockade) |
|---|---|
| Mechanism | Selective competitive antagonist at the histamine H2 receptor on gastric parietal cells, blocking histamine-stimulated gastric acid secretion (basal, nocturnal, food-stimulated, and pentagastrin- stimulated) — produces ~50-90% acid suppression depending on dose. In allergic reactions and chemotherapy infusion reactions, the H2 antagonism complements H1 antagonist (diphenhydramine) blockade — histamine acts on both H1 (bronchospasm, vasodilation, urticaria, pruritus) AND H2 (vasodilation, gastric secretion, cardiac inotropy) receptors, and combined H1 + H2 blockade is superior to either alone for prevention and treatment of urticaria, mild anaphylactoid reactions, and chemotherapy infusion reactions (paclitaxel, carboplatin retreatment, monoclonal antibodies). Famotidine is preferred among H2 antagonists in oncology because of lack of CYP-mediated drug interactions (cimetidine inhibits C... |
| Typical dosing | CHEMOTHERAPY PREMEDICATION (paclitaxel, rituximab, monoclonal antibodies — adult): 20 mg IV 30 min before infusion (paired with diphenhydramine 25-50 mg IV + dexamethasone). ACUTE ALLERGIC / INFUSION REACTION ADJUNCT (combined with H1): 20 mg IV every 6 h × 24 h. Acid suppression (PUD, GERD): 20-40 mg PO BID or 20 mg IV q12h. Stress ulcer prophylaxis: 20 mg IV q12h. Pediatric (≥1 year): 0.25 mg/kg IV q6-12h, max 40 mg/day. Renal adjustment: CrCl 30-60 → 20 mg q24h (or half-dose at usual interval); CrCl <30 → 20 mg q24-48h or 50% dose; hemodialysis → dose post-dialysis. Hepatic: no adjustment. Onset of acid suppression IV: ~30 min; oral: ~1 h. Duration acid suppression: 10-12 h. Long-term to... |
| Ukraine registered | True |
| NSZU reimbursed | True |
| Ukraine last verified | 2026-04-27 |
Notes
Standard H2 component of chemotherapy premedication, paired with H1 antihistamine (diphenhydramine) and corticosteroid (dexamethasone). Particularly important before paclitaxel (Cremophor vehicle hyper- sensitivity), rituximab, daratumumab, and other monoclonal antibodies with significant infusion reaction rates. Combined H1 + H2 blockade is empirically superior to H1 alone for prevention of mild-to-moderate hypersensitivity reactions (Lieberman-Goodyear, 2010). NEVER a substitute for epinephrine in true anaphylaxis — H1 + H2 + steroid treats pruritus, urticaria, mild bronchospasm, but does not reverse hypotension or upper airway edema. Famotidine preferred over cimetidine in oncology because of clean DDI profile (cimetidine inhibits multiple CYPs causing exposure increases of warfarin, theophylline, phenytoin, TKIs, vincristine — major hazard); ranitidine withdrawn worldwide 2019-2020 for NDMA contamination. CRITICAL: H2 antagonists raise gastric pH → reduce absorption of pH-dependent oral oncology agents (dasatinib, erlotinib, gefitinib, dabigatran, atazanavir) — separate by 2-10 h or substitute / time TKI dose. Renal dose adjustment important to prevent confusion / delirium in...
Used By
No reverse references found in the YAML corpus.