Generic
Terbinafine
37 brands available in the market
At a glance
Terbinafine is an allylamine antifungal used for skin and nail fungal infections. It kills fungi by inhibiting squalene epoxidase, preventing ergosterol synthesis.
Description
Terbinafine is an allylamine antifungal that inhibits squalene epoxidase, preventing ergosterol (an essential component of fungal cell membranes) synthesis. This leads to accumulation of squalene and increased membrane permeability, causing fungal cell death. It has fungicidal activity against dermatophytes and some yeasts.
Indications
- Onychomycosis (nail fungal infections)
- Tinea capitis
- Tinea pedis (athlete's foot), tinea corporis, tinea cruris
- Cutaneous candidiasis, pityriasis versicolor
Therapeutic class
Other Antifungal & Topical Antifungal Preparations
Pharmacological class
Allylamine Antifungal
Pharmacology
Terbinafine inhibits squalene epoxidase, preventing ergosterol synthesis, causing accumulation of squalene and increased membrane permeability. It exhibits fungicidal activity against dermatophytes and some yeasts.
Mechanism of action
Destroys fungal cell membranes by inhibiting squalene epoxidase.
Dosage
Adult Dose (Oral):
- Fingernail: 250 mg/day for 6 weeks
- Toenail: 250 mg/day for 12 weeks
Pediatric Dose (Granules, Tinea Capitis):
- <25 kg: 125 mg/day for 6 weeks
- 25-35 kg: 187.5 mg/day for 6 weeks
- >35 kg: 250 mg/day for 6 weeks
Topical (Cream/Spray):
- Tinea corporis/cruris: 1-2 times daily (1-2 weeks)
- Tinea pedis: 1-2 times daily (1 week)
- Candidiasis/pityriasis versicolor: 1-2 times daily (2 weeks)
Administration
- Oral: Take with or without food
- Topical: Clean and dry the affected area; apply a thin layer
- Cream/spray: For external use only; avoid contact with eyes
Missed dose
If you miss a dose, take it as soon as you remember; if almost time for the next dose, skip it; do not double the dose.
Side effects
Common Side Effects:
- GI symptoms (diarrhea, dyspepsia, abdominal pain)
- Elevated liver enzymes, rash, urticaria, pruritus
- Taste disturbances
- Topical: Application site burning, itching
Serious (Rare):
- Liver failure, severe skin reactions (SJS, TEN)
- Neutropenia, thrombocytopenia
- Angioedema, anaphylaxis
Precautions & warnings
- Do not use in chronic or active liver disease (oral)
- Perform liver function tests (ALT, AST) before treatment
- Do not use in renal impairment (CrCl <50)
- Caution in pregnancy and lactation
Contraindications
- Hypersensitivity to terbinafine
- Chronic or active liver disease (oral)
- Lactation
Drug interactions
- CYP450 2D6 inhibitors (TCA, SSRI, beta-blockers, Class IC antiarrhythmics): Levels increased by terbinafine; monitoring required
- Rifampicin: Decreased terbinafine concentration
- Cimetidine: Increased terbinafine concentration
Food interactions
Caution is advised when consuming alcohol with Terbinafine (risk of liver damage); consult your doctor.
Use in pregnancy
Use in Pregnancy: Generally safe; animal studies show low or no adverse effects; limited human data; consult your doctor.
Pregnancy Category: C — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Probably unsafe; limited data suggests drug may pass into breast milk and harm the baby; do not use while breastfeeding; consult your doctor.
Pediatric use
Indicated for children (age/weight-based dosing)
Geriatric use
No differences in dosage or side effects between elderly and younger patients
Renal / hepatic impairment
Renal Impairment: CrCl <50: Do not use; consult your doctor.
Hepatic Impairment: Do not use in chronic or active liver disease; consult your doctor.
Overdose effects
Overdose (up to 5 g) may cause nausea, abdominal pain, dizziness, rash, frequent urination; provide symptomatic treatment.
Storage conditions
Store below 30°C in a cool and dry place, protected from light; keep out of reach of children.
Chemical structure
Terbinafine