MOTRIN IB
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MOTRIN IB (MOTRIN IB).
Reversibly inhibits cyclooxygenase-1 and -2 (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis, which decreases inflammation, pain, and fever.
| Metabolism | Primarily hepatic via cytochrome P450 2C9 (CYP2C9) and, to a lesser extent, CYP2C8; undergoes glucuronidation. |
| Excretion | Renal excretion of conjugated metabolites (primarily glucuronide and sulfate) accounts for approximately 90% of an absorbed dose; less than 1% is excreted unchanged. Biliary/fecal elimination constitutes about 10%. |
| Half-life | Terminal elimination half-life is approximately 2 hours (range 1.8–2.5 hours) in adults. In patients with hepatic impairment or advanced age, half-life may be prolonged. The short half-life supports dosing every 6–8 hours for analgesia. |
| Protein binding | Approximately 99% bound to plasma albumin. |
| Volume of Distribution | Apparent volume of distribution is 0.15 L/kg (range 0.10–0.20 L/kg), consistent with low tissue penetration and high plasma protein binding. |
| Bioavailability | Oral: ~80% (rapidly and completely absorbed; first-pass metabolism reduces absolute bioavailability to 80% of the dose). |
| Onset of Action | Oral: 30–60 minutes for analgesic effect; peak plasma levels at 1–2 hours. |
| Duration of Action | Duration of analgesic effect is 4–6 hours following a single oral dose, corresponding to the dosing interval. Antipyretic effect lasts approximately 6–8 hours. |
| Molecular Weight | 206.29 |
200-400 mg orally every 4-6 hours as needed; maximum 1200 mg in 24 hours.
| Dosage form | TABLET |
| Renal impairment | GFR 30-60 mL/min: no adjustment needed; GFR 10-29 mL/min: reduce dose by 25-50%; GFR <10 mL/min: avoid use or reduce dose by 50%. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use. |
| Pediatric use | 6 months to 12 years: 5-10 mg/kg/dose every 6-8 hours; maximum 40 mg/kg/day or single doses not exceeding 400 mg. |
| Geriatric use | Initiate at the lowest effective dose, typically 200-400 mg every 6-8 hours; maximum 1200 mg/day; monitor renal function and potential for GI bleeding. |
| 1st trimester | Avoid due to potential risk of miscarriage and congenital malformations (cardiac defects, gastroschisis). Use only if clearly needed and benefits outweigh risks. |
| 2nd trimester | Caution: Use lowest effective dose and shortest duration. Associated with oligohydramnios, premature closure of ductus arteriosus, and fetal renal dysfunction. |
| 3rd trimester | Contraindicated: May cause premature constriction of ductus arteriosus, persistent pulmonary hypertension, oligohydramnios, and prolong bleeding time. |
Clinical note
Comprehensive clinical and safety monograph for MOTRIN IB (MOTRIN IB).
| Placental transfer | Crosses placenta; fetal serum levels reach ~50% of maternal levels. |
| Breastfeeding | Enters breast milk in low amounts; considered compatible with breastfeeding. Avoid if infant has thrombocytopenia or bleeding disorders. Monitor for rash, diarrhea, or drowsiness. |
■ FDA Black Box Warning
Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious gastrointestinal adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. Elderly patients and patients with a prior history of peptic ulcer disease and/or GI bleeding are at greater risk. Additionally, NSAIDs cause an increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal. This risk may increase with duration of use. Patients with cardiovascular disease or risk factors for cardiovascular disease may be at greater risk.
| Serious Effects |
Hypersensitivity to ibuprofen or NSAIDsHistory of asthma, urticaria, or allergic reactions after aspirin/NSAIDsActive peptic ulcer disease or GI bleedingSevere heart failure (NYHA III-IV)Coronary artery bypass graft (CABG) surgery perioperativelyThird trimester of pregnancySignificant renal impairment (CrCl <30 mL/min)Known intracranial hemorrhage or bleeding diathesis
| Precautions | Cardiovascular thrombotic events; gastrointestinal bleeding, ulceration, and perforation; hypertension; heart failure; renal toxicity; anaphylactoid reactions; serious skin reactions such as Stevens-Johnson syndrome; avoid use in late pregnancy |
Loading safety data…
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | First trimester: Increased risk of miscarriage and cardiac defects (odds ratio 1.86 for cardiovascular malformations). Second trimester: Risk of oligohydramnios and fetal renal dysfunction. Third trimester: Known risk of premature closure of ductus arteriosus, persistent pulmonary hypertension, oligohydramnios, and necrotizing enterocolitis. Use contraindicated after 30 weeks gestation. |
| Fetal Monitoring | Monitor maternal blood pressure, renal function (serum creatinine, urinalysis), and signs of gastrointestinal bleeding. Fetal ultrasound for oligohydramnios and ductus arteriosus patency if used in second or third trimester. Assess fetal growth if used long-term. |
| Fertility Effects | Reversible inhibition of prostaglandin synthesis may impair ovulation and luteal phase function. Use may delay conception due to luteinized unruptured follicle syndrome. Effects resolve upon discontinuation. |
| Food/Dietary |
| Concomitant intake of alcohol may increase risk of gastrointestinal bleeding. No specific food restrictions; however, taking with food may reduce GI irritation. Avoid grapefruit juice? No significant interaction known. |
| Clinical Pearls | Motrin IB (ibuprofen) is a nonsteroidal anti-inflammatory drug (NSAID) used for mild to moderate pain, fever, and inflammation. Onset of analgesia is within 30-60 minutes. It is more effective than acetaminophen for inflammatory pain. Maximum single OTC dose is 400 mg; maximum daily OTC dose is 1200 mg. Chronic use increases risk of GI bleeding, renal impairment, and cardiovascular events. Avoid in patients with significant renal impairment (eGFR <30), active peptic ulcer disease, or prior hypersensitivity to NSAIDs. Use with caution in patients with hypertension, heart failure, or on anticoagulants. Ibuprofen may reduce the cardioprotective effect of low-dose aspirin if taken simultaneously; separate dosing by at least 2 hours. |
| Patient Advice | Take with food or milk to reduce stomach upset. · Do not exceed 1200 mg (6 tablets of 200 mg) in 24 hours. · Avoid alcohol while taking this medication to reduce risk of stomach bleeding. · Stop use and consult a doctor if pain worsens or lasts more than 10 days, or if fever lasts more than 3 days. · Do not take with other NSAIDs (e.g., naproxen, aspirin) unless directed by a healthcare provider. · Seek medical attention immediately if signs of allergic reaction (rash, hives, swelling, difficulty breathing) or stomach bleeding (black/bloody stools, vomiting blood) occur. |