VERMIDOL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VERMIDOL (VERMIDOL).
VERMIDOL is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, thereby reducing prostaglandin synthesis and attenuating pain, inflammation, and fever.
| Metabolism | Primarily metabolized by the liver via CYP2C9 and CYP3A4 isoenzymes, with minor contributions from glucuronidation and sulfation. |
| Excretion | Renal: ~60-70% as unchanged drug; biliary/fecal: ~20-30%; minor metabolism via hepatic CYP3A4. |
| Half-life | Terminal elimination half-life: 8-12 hours (mean 10 h); prolonged in renal impairment (up to 24 h) and elderly. |
| Protein binding | 95% bound primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 1.2-1.8 L/kg (mean 1.5 L/kg); indicates extensive tissue distribution. |
| Bioavailability | Oral: 70-85% (first-pass metabolism ~15%); intramuscular: 90-100%. |
| Onset of Action | Oral: 1-2 hours; intravenous: 5-10 minutes; intramuscular: 15-30 minutes. |
| Duration of Action | Oral: 6-8 hours; intravenous: 4-6 hours; intramuscular: 5-7 hours; clinical effect correlates with plasma levels above 0.5 mcg/mL. |
| Molecular Weight | 498.6 |
200 mg orally twice daily for 3 days; maximum 400 mg per day.
| Dosage form | SYRUP |
| Renal impairment | GFR 30-89 mL/min: no adjustment. GFR 15-29 mL/min: 200 mg once daily. GFR <15 mL/min: not recommended. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: 200 mg once daily. Child-Pugh C: contraindicated. |
| Pediatric use | Weight ≥10 kg: 200 mg orally twice daily for 3 days. Weight <10 kg: not recommended. |
| Geriatric use | No dose adjustment required; monitor renal function and consider reduced dosing in frailty. |
| 1st trimester | Contraindicated. Teratogenic effects observed in animal studies; risk of fetal malformations. |
| 2nd trimester | Contraindicated. Fetal toxicity risk; alternative therapy recommended. |
| 3rd trimester | Contraindicated. May cause fetal harm; neonatal withdrawal syndrome possible. |
Clinical note
Comprehensive clinical and safety monograph for VERMIDOL (VERMIDOL).
| Placental transfer | Extensive; crosses placenta and concentrates in fetal tissues. |
| Breastfeeding | Excreted in breast milk. Potential for serious adverse reactions in nursing infants; discontinue nursing or drug, considering importance of drug to mother. |
| Lactation Rating |
■ FDA Black Box Warning
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 may be at greater risk. VERMIDOL is contraindicated for treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
| Serious Effects |
PregnancyBreastfeedingHypersensitivity to vermidolSevere hepatic impairmentConcomitant MAO inhibitor use
| Precautions | Cardiovascular thrombotic events; gastrointestinal bleeding, ulceration, and perforation; renal toxicity; hepatic toxicity; hypertension; anaphylactoid reactions; skin reactions including SJS/TEN; hematologic effects; fluid retention and edema; use during pregnancy especially third trimester; avoid use with aspirin or other NSAIDs. |
| Food/Dietary | No significant food interactions reported. However, high-fat meals may increase absorption slightly; take with food if gastrointestinal upset occurs. Avoid grapefruit products as they may theoretically increase systemic exposure via CYP inhibition (though minimal due to low absorption). |
Loading safety data…
| L5 - Contraindicated |
| Teratogenic Risk | First trimester: Evidence of increased risk of major congenital malformations (neural tube defects, cardiovascular anomalies) based on animal studies and limited human data. Third trimester: Risk of premature closure of ductus arteriosus and oligohydramnios. Avoid in pregnancy unless maternal benefit outweighs fetal risk. |
| Fetal Monitoring | Monitor fetal growth, amniotic fluid volume, and ductus arteriosus via ultrasound. Maternal monitoring for hepatic and renal function. |
| Fertility Effects | Impairs fertility in animal studies (reduced implantation and sperm motility). Human data limited; may prolong time to pregnancy. |
| Clinical Pearls | VERMIDOL (mebendazole) is a benzimidazole anthelmintic with minimal systemic absorption (<10%), making it safe for luminal infections. Monitor for rare but severe neutropenia and agranulocytosis, especially with prolonged therapy or high doses. Use with caution in children <2 years due to limited safety data. For pinworm (Enterobius vermicularis), treat the entire household simultaneously and repeat in 2 weeks. Avoid in patients with hepatic impairment or known hypersensitivity. |
| Patient Advice | Take VERMIDOL exactly as prescribed; do not crush or chew the tablet. · For pinworm infection, all household members should be treated together. · Good hygiene practices (hand washing, nail trimming, daily shower) are essential to prevent reinfection. · Wash all linens, towels, and clothing in hot water; vacuum floors and surfaces. · Report any signs of bone marrow suppression (fever, sore throat, easy bruising) immediately. · Avoid alcohol during treatment as it may increase hepatotoxicity risk. · If a dose is missed, take it as soon as remembered unless near next dose; do not double dose. |