MECLOMEN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MECLOMEN (MECLOMEN).
Meclomen (meclofenamate) is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis. This results in anti-inflammatory, analgesic, and antipyretic effects.
| Metabolism | Meclomen is metabolized primarily via hepatic glucuronidation. Minor involvement of cytochrome P450 (CYP) enzymes (likely CYP3A4 and CYP2C9) observed. Renal excretion of unchanged drug and metabolites. |
| Excretion | Renal (approximately 70% as metabolites, <5% unchanged); fecal/biliary (approximately 30% as metabolites). |
| Half-life | Terminal elimination half-life: 0.8–1.1 hours for meclofenamic acid; 2–4 hours for metabolites. Short half-life requires frequent dosing (e.g., every 6–8 hours) for sustained effect. |
| Protein binding | Greater than 99% bound, primarily to albumin. |
| Volume of Distribution | Approximately 0.3 L/kg; distributes into synovial fluid but low penetration into CNS. |
| Bioavailability | Oral: approximately 100% (well absorbed). |
| Onset of Action | Oral: 30–60 minutes for analgesic effect; peak plasma concentrations at 0.5–2 hours. |
| Duration of Action | Analgesic effect: 4–6 hours (short duration necessitates frequent dosing). Anti-inflammatory effect may require several days of therapy to become apparent. |
| Molecular Weight | 296.15 Da (as meclofenamic acid; meclomen is meclofenamate sodium with MW 336.32 Da, but active moiety is meclofenamic acid) |
50-100 mg orally every 6-8 hours; maximum 400 mg/day.
| Dosage form | CAPSULE |
| Renal impairment | GFR 30-60 mL/min: avoid use or reduce dose; GFR <30 mL/min: contraindicated. |
| Liver impairment | Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid use. |
| Pediatric use | Not recommended for children under 14 years; safety not established. |
| Geriatric use | Start at lowest effective dose; reduce dose by 50% due to increased risk of GI bleeding and renal impairment. |
| 1st trimester | Avoid. Risk of cardiovascular closure and neural tube defects; NSAIDs are generally not recommended in first trimester unless absolutely necessary. |
| 2nd trimester | Avoid if possible; may cause oligohydramnios and fetal renal impairment; use only if benefit clearly outweighs risk. |
| 3rd trimester | Contraindicated. Risk of premature closure of ductus arteriosus, oligohydramnios, and neonatal complications (e.g., pulmonary hypertension, renal failure). |
Clinical note
Comprehensive clinical and safety monograph for MECLOMEN (MECLOMEN).
| Placental transfer | Crosses placenta; animal studies indicate transfer, and human data suggest significant fetal exposure with potential adverse effects. |
| Breastfeeding | Excreted into breast milk in low amounts. Use with caution, especially in mothers nursing infants with known NSAID sensitivity, thrombocytopenia, or renal impairment. Monitor infant for adverse effects such as drowsiness, gastrointestinal bleeding, or platelet dysfunction. |
■ 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. Risk may increase with duration of use. Patients with cardiovascular disease or risk factors may be at greater risk. NSAIDs are contraindicated for the treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
| Serious Effects |
Known hypersensitivity to meclofenamate or any component of the formulationHistory of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDsTreatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgeryActive gastrointestinal bleeding or perforationHistory of peptic ulcer disease or recurrent GI bleedingThird trimester of pregnancy (after 30 weeks gestation)Advanced renal disease (unless dialysis patients)
| Precautions | Cardiovascular thrombotic events; gastrointestinal adverse events including bleeding, ulceration, and perforation; renal toxicity (elevated serum creatinine, acute renal failure); hepatic effects (elevated liver enzymes, hepatotoxicity); anaphylactoid reactions; exacerbation of asthma; hypertension; fluid retention; serious skin reactions (e.g., Stevens-Johnson syndrome). Use with caution in elderly, patients with history of peptic ulcer disease, renal impairment, or hepatic impairment. |
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| Lactation Rating | L3 (Moderately Safe) – limited data suggest low risk, but caution advised. |
| Teratogenic Risk | First trimester: Avoid due to potential for cardiovascular and neural tube defects. Second and third trimesters: Contraindicated; may cause premature closure of ductus arteriosus, oligohydramnios, and neonatal renal impairment. |
| Fetal Monitoring | Monitor amniotic fluid volume, ductus arteriosus patency (fetal echocardiography), and fetal renal function. Maternal monitoring of blood pressure, renal function, and gastrointestinal symptoms. |
| Fertility Effects | May impair fertility in women via inhibition of prostaglandin synthesis affecting ovulation; reversible upon discontinuation. |
| Food/Dietary | Take with food or milk to minimize GI irritation. Avoid alcohol as it increases risk of GI bleeding. No specific food restrictions beyond GI comfort. |
| Clinical Pearls | Meclofenamate is a non-selective NSAID with a short half-life; take with food to reduce GI irritation. Monitor renal function in elderly/dehydrated patients; avoid in renal impairment. Contraindicated in aspirin-sensitive asthma. May potentiate warfarin, lithium, methotrexate, and diuretics. |
| Patient Advice | Take with food or milk to reduce stomach upset. · Avoid alcohol while taking this medication. · Report signs of GI bleeding (black/bloody stools, coffee-ground vomitus), rash, weight gain, or edema. · Do not take with other NSAIDs or over-the-counter pain relievers without consulting a doctor. · Avoid prolonged sun exposure; use sunscreen as this drug may increase photosensitivity. |