VERMOX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VERMOX (VERMOX).
Binds to β-tubulin in parasitic cells, inhibiting microtubule polymerization, thereby impairing glucose uptake and causing energy depletion and parasite death.
| Metabolism | Hepatic metabolism via unidentified enzymes; undergoes extensive first-pass metabolism; metabolites are excreted primarily in bile. |
| Excretion | Fecal (90%) as unchanged drug and metabolites; renal (<10%) |
| Half-life | 2-8 hours (terminal half-life, may be prolonged in hepatic impairment or obstruction) |
| Protein binding | 90-95% (primarily to albumin) |
| Volume of Distribution | 0.5-1.0 L/kg (large Vd indicating extravascular distribution) |
| Bioavailability | Oral: 1-10% (poor and variable due to extensive first-pass metabolism) |
| Onset of Action | Oral: 2-4 hours (paralysis of helminths) |
| Duration of Action | 24-48 hours (continued expulsion of dead worms) |
| Molecular Weight | 314.34 |
| Action Class | Cell wall active agent -Extended spectrum Penicillin |
| Brand Substitutes | Cipmox 500 Capsule, Tidoxyl 500mg Capsule, Actimox 500mg Capsule, SB Mox 500mg Capsule, Mitmox 500mg Capsule, Ranoxyl 125mg Syrup, Nodimox 125mg Syrup, Biomoxil 125mg Syrup, Alkamox 125mg Syrup, Swimox 125mg Syrup, Amoxipen 250mg Capsule, Hipen A 250mg Capsule, Moxipal 250mg Capsule, Amoxil 250mg Capsule, Moxikem 250mg Capsule |
Mebendazole 100 mg orally twice daily for 3 days for pinworm, whipworm, hookworm, and roundworm infections. For pinworm, may repeat after 2 weeks. For hookworm and whipworm, may require longer courses.
| Dosage form | TABLET, CHEWABLE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Insufficient data for severe renal impairment (GFR <30 mL/min). Caution advised. |
| Liver impairment | Contraindicated in patients with hepatic impairment (Child-Pugh class B or C) due to risk of toxicity. Use with caution in mild impairment (Child-Pugh class A) with monitoring. |
| Pediatric use | Children ≥1 year: 100 mg orally twice daily for 3 days. For children <1 year: not recommended (safety and efficacy not established). |
| Geriatric use | No specific dose adjustment required. Use standard adult dosing with caution for age-related renal/hepatic decline. |
| 1st trimester | Contraindicated due to known teratogenicity in animals; use only if potential benefit outweighs risk. |
| 2nd trimester | Use with caution; limited human data suggest low risk, but avoid in first choice. |
| 3rd trimester | Generally avoided; consider alternative therapy. |
Clinical note
Comprehensive clinical and safety monograph for VERMOX (VERMOX).
| Placental transfer | High; crosses placenta in animal studies; human data limited but expected. |
| Breastfeeding | Excreted in breast milk in low amounts; manufacturer advises cautious use. Monitor infant for diarrhea or adverse effects. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to mebendazolePregnancy (especially first trimester)
| Precautions | Hematologic effects: neutropenia has occurred, especially at high doses; monitor complete blood counts during prolonged therapy., Gastrointestinal effects: abdominal pain, diarrhea, and nausea may occur, particularly with heavy infections., Hepatotoxicity: elevated liver enzymes reported; use caution in patients with hepatic impairment., Hypersensitivity reactions: discontinue if skin rash, urticaria, or erythema multiforme occurs., Pregnancy: avoid use, especially in first trimester; animal studies have shown embryotoxicity and teratogenicity. |
| Food/Dietary | No significant food interactions. Grapefruit juice does not affect mebendazole. High-fat meals may slightly increase absorption but not clinically relevant. |
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| L2 (Safer) |
| Teratogenic Risk | FDA Pregnancy Category C. Animal studies have shown embryotoxic and teratogenic effects at high doses; no adequate human studies. First trimester: Risk cannot be excluded; use only if clearly needed. Second/third trimester: Limited data suggest no increased risk of major malformations with short-term use. |
| Fetal Monitoring | No specific monitoring required; however, due to potential hepatotoxicity, monitor liver function tests if prolonged use. Fetal ultrasound not routinely indicated unless overdose or toxicity suspected. |
| Fertility Effects | No known adverse effects on fertility in humans. Animal studies at high doses have shown reduced fertility; clinical significance is unknown. |
| Clinical Pearls | Mebendazole (Vermox) is poorly absorbed systemically, making it the drug of choice for intestinal nematodes. For trichinellosis and echinococcosis, higher doses and longer courses are used but require monitoring for neutropenia. May cause rare but severe skin reactions like Stevens-Johnson syndrome. Avoid in pregnancy (category C). |
| Patient Advice | Chew or crush the tablet before swallowing; can be taken with or without food. · Take exactly as prescribed; a second course may be needed after 2-3 weeks. · Wash hands frequently and practice good hygiene to prevent reinfection. · Wash bed linens and underwear in hot water daily during treatment. · May cause abdominal pain, diarrhea, or dizziness; report severe reactions like rash or fever. |