Home
BackTerbinafine Data - Uses, Dosage, Drug class, Brand name, Warnings, etc
| Pharmacology |
Terbinafine is a synthetic allylamine antifungal agent. Inhibits fungal ergosterol synthesis via squalene epoxidase, disrupting cell membrane integrity. Active orally and topically against dermatophyte infections; less active than azoles against yeast species. |
|---|---|
| Adult Dosage |
PO for onychomycosis: - Fingernails: 250 mg once daily for 6 weeks - Toenails: 250 mg once daily for 12 weeks - Reduce dosage in severe hepatic/renal dysfunction Topical for tinea corporis/cruris, cutaneous candidiasis: - Apply 1% cream twice daily for 1 week Topical for tinea pedis: - Apply 1% solution or spray twice daily for 1 week - Cream: May require up to 4 weeks (plantar infections) Topical for tinea versicolor: - Apply 1% solution or spray twice daily for 1 week |
| Pediatric Dosage | <12 yr: Safety and efficacy not established. |
| Dosage Forms |
- Cream: 1% - Topical Spray: 1% - Topical Solution: 1% - Tablet: 250 mg |
| Pharmacokinetics |
Absorption: - 70–80% orally absorbed, unaffected by food Peak Concentrations: - 250 mg dose: 0.9 mg/L (3.1 µmol/L) within 2 hr - 500 mg dose: 2 mg/L (6.9 µmol/L) within 2 hr Distribution: - Highly lipophilic; Vd = 13.5 L/kg Metabolism: - Extensively metabolized to inactive metabolites Elimination Half-life: - Primary: 11–16 hr - Secondary: 200–400 hr (due to adipose tissue release) |
| Adverse Reactions |
Frequent (oral therapy): - Dyspepsia, abdominal pain, diarrhea, skin reactions, malaise, lethargy, taste disturbance Rare: - Hepatic failure (reported with onychomycosis treatment) Avoid in patients with liver disease. |
| Drug Interactions |
- Inhibits CYP2D6, increasing levels of drugs metabolized by this enzyme - Rifampin: Increases terbinafine clearance by 100% - Cimetidine: Decreases terbinafine clearance by 33% |
| Parameters to Monitor |
- Baseline AST, ALT - Repeat if hepatotoxicity symptoms occur |
References
Hand of Clinical Drug Data