IBUPROFEN AND FAMOTIDINE
Clinical safety rating: avoid
ACE inhibitors and ARBs may have diminished antihypertensive effect Increases risk of serious cardiovascular thrombotic events and GI bleeding.
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis, which decreases inflammation, pain, and fever. Famotidine is a histamine H2-receptor antagonist that inhibits gastric acid secretion by blocking histamine at H2 receptors on gastric parietal cells.
| Metabolism | Ibuprofen is primarily metabolized by CYP2C9 and CYP2C8. Famotidine is minimally metabolized in the liver (30-35%) via oxidative pathways; the remainder is excreted unchanged in urine. |
| Excretion | Ibuprofen: Renal excretion of metabolites (90%) and unchanged drug (<10%); biliary/fecal (minor). Famotidine: Renal excretion of unchanged drug (65-70%); metabolites (25-30%); biliary/fecal (minor). |
| Half-life | Ibuprofen: Terminal half-life 2-4 hours (normal renal function); prolonged to 3-6 hours in elderly or hepatic impairment. Famotidine: Terminal half-life 2.5-3.5 hours (normal renal function); extended to >20 hours in severe renal impairment (CrCl <10 mL/min). |
| Protein binding | Ibuprofen: >99% bound to albumin (mostly). Famotidine: 15-20% bound to plasma proteins (albumin). |
| Volume of Distribution | Ibuprofen: 0.1-0.2 L/kg (low, reflects high protein binding and limited tissue distribution). Famotidine: 1.1-1.4 L/kg (suggests extensive extravascular distribution). |
| Bioavailability | Ibuprofen: Oral: 80-100% (well absorbed with food causing slight delay). Famotidine: Oral: 40-50% (first-pass metabolism; reduced with food). |
| Onset of Action | Ibuprofen: Oral immediate-release: 30-60 minutes (analgesic/anorectic effect). Famotidine: Oral: 1 hour (acid suppression); maximum effect at 1-3 hours. |
| Duration of Action | Ibuprofen: 4-6 hours (analgesic effect); longer with extended-release formulations. Famotidine: Acid suppression lasts 10-12 hours (dose-dependent). |
One tablet (ibuprofen 800 mg/famotidine 26.6 mg) orally three times daily.
| Dosage form | TABLET |
| Renal impairment | Contraindicated if CrCl < 30 mL/min. For CrCl 30-49 mL/min, reduce famotidine dose by 50% (not possible with fixed combination; use alternative therapy). |
| Liver impairment | No specific dose adjustment for Child-Pugh A or B; avoid in severe hepatic impairment (Child-Pugh C) due to ibuprofen component. |
| Pediatric use | Not established for combination; ibuprofen 5-10 mg/kg/dose (max 400 mg) q6-8h as separate agent; famotidine 0.5 mg/kg/dose (max 20 mg) q12h for pediatric use. |
| Geriatric use | Start at lowest effective dose; monitor renal function; avoid if CrCl < 30 mL/min; increased risk of GI bleeding and renal impairment. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
ACE inhibitors and ARBs may have diminished antihypertensive effect Increases risk of serious cardiovascular thrombotic events and GI bleeding.
| FDA category | Positive |
| Breastfeeding | Ibuprofen: Excretion into breast milk is low (M/P ratio 0.007-0.24); considered compatible with breastfeeding. Famotidine: Excreted in breast milk (M/P ratio approximately 0.25-0.71); infant exposure is low; generally acceptable with caution. Combined use: Limited data; monitor infant for gastrointestinal effects. |
| Teratogenic Risk |
■ FDA Black Box Warning
Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. NSAIDs are contraindicated in the setting of coronary artery bypass graft (CABG) surgery.
| Common Effects | fever |
| Serious Effects |
History of allergic reaction to ibuprofen, famotidine, or any other NSAID. History of aspirin-sensitive asthma. Coronary artery bypass graft (CABG) surgery. Active peptic ulcer disease or GI bleeding. Advanced renal disease. Pregnancy at 30 weeks gestation and later (risk of premature closure of ductus arteriosus).
| Precautions | Cardiovascular risk: Increased risk of serious cardiovascular thrombotic events. Gastrointestinal risk: Serious GI adverse events including bleeding, ulceration, and perforation. Renal toxicity: Monitor renal function. Hepatic effects: Elevation of liver enzymes. Anaphylactoid reactions: Bronchospasm in aspirin-sensitive asthma. Hypertension: Can worsen blood pressure control. Fluid retention and edema. |
Loading safety data…
| First trimester: Ibuprofen is associated with increased risk of miscarriage and congenital malformations (cardiac defects, gastroschisis). Famotidine is generally considered low risk, but limited data. Second trimester: Ibuprofen use is linked to fetal renal dysfunction and oligohydramnios; famotidine appears safe. Third trimester: Ibuprofen is contraindicated due to risk of premature closure of ductus arteriosus, oligohydramnios, and neonatal pulmonary hypertension; famotidine has no known fetal risks. |
| Fetal Monitoring | Maternal: Renal function, blood pressure, signs of gastrointestinal bleeding. Fetal: Ultrasound for oligohydramnios and ductus arteriosus patency if ibuprofen used in second/third trimester; growth monitoring. |
| Fertility Effects | Ibuprofen may reversibly impair female fertility by affecting ovulation (prostaglandin inhibition); effects resolve upon discontinuation. Famotidine has no known impact on fertility. |