TOLMETIN SODIUM
Clinical safety rating: avoid
Positive evidence of fetus risks but benefits may outweigh risks in some cases
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis. It has anti-inflammatory, analgesic, and antipyretic effects.
| Metabolism | Primarily hepatic metabolism via cytochrome P450 enzymes, including CYP2C9 and CYP2C8, with significant first-pass metabolism. |
| Excretion | Renal excretion (~90% as unchanged drug and conjugates), with fecal excretion (~10% as metabolites) |
| Half-life | Terminal elimination half-life is approximately 4.5–6 hours (mean 5 hours); may be prolonged in elderly or patients with renal impairment |
| Protein binding | Approximately 99% bound to plasma albumin |
| Volume of Distribution | 0.1–0.2 L/kg (low Vd, indicating distribution primarily in extracellular fluid) |
| Bioavailability | Oral: 100% (well absorbed; first-pass metabolism is negligible) |
| Onset of Action | Oral: 30–60 minutes (therapeutic effect for rheumatoid arthritis may take 1–2 weeks of continuous dosing) |
| Duration of Action | 4–6 hours per dose; anti-inflammatory effect requires regular dosing for sustained benefit |
400 mg orally three times daily; maximum 1800 mg/day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-59 mL/min: 50% of normal dose; GFR <30 mL/min: contraindicated. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B or C: use with caution, reduce dose by 50%. |
| Pediatric use | 2 years and older: 20 mg/kg/day orally in 3-4 divided doses; maximum 30 mg/kg/day. |
| Geriatric use | Start at lowest effective dose (e.g., 400 mg once daily) and titrate cautiously; monitor renal function and gastrointestinal tolerability. |
| 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.
| Breastfeeding | Limited data; tolinetin is excreted into breast milk in low amounts (M/P ratio unknown). Milk concentrations <1% of maternal dose. Considered compatible with breastfeeding due to very low infant exposure, but caution with prolonged use due to potential adverse effects in neonate. |
| Teratogenic Risk | First trimester: Risk of congenital malformations, particularly cardiac defects (OR 1.83 for NSAIDs) and gastroschisis (OR 2.5). Second trimester: Increased risk of oligohydramnios and fetal renal impairment. Third trimester: Premature closure of ductus arteriosus, persistent pulmonary hypertension, oligohydramnios, and necrotizing enterocolitis. Avoid after 30 weeks gestation. |
■ 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 increase with duration of use. Patients with cardiovascular disease or risk factors for cardiovascular disease may be at greater risk. Tolmetin is contraindicated for the treatment of peri-operative pain in the setting of coronary artery bypass graft (CABG) surgery.
| Common Effects | rheumatoid arthritis |
| Serious Effects |
Hypersensitivity to tolmetin or other NSAIDs; history of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs; peri-operative pain in CABG surgery; active gastrointestinal bleeding; severe heart failure; advanced renal disease.
| Precautions | Cardiovascular thrombotic events; gastrointestinal bleeding, ulceration, and perforation; renal toxicity; hepatic toxicity; anaphylactoid reactions; hypertension; fluid retention; exacerbation of asthma; photosensitivity; hematologic effects; use in pregnancy (avoid in third trimester). |
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| Fetal Monitoring | Monitor maternal renal function, blood pressure, and signs of fluid retention. Fetal ultrasound to assess amniotic fluid volume and ductus arteriosus flow after 20 weeks. Perform fetal echocardiography if used beyond 30 weeks. Assess for oligohydramnios if used for >48 hours. |
| Fertility Effects | Potential reversible inhibition of ovulation via altered prostaglandin synthesis; may delay conception. No permanent effect on fertility. Use with caution in women attempting to conceive. |