Dosage Forms. Tablet: 250 mg; Granules, Oral: 125 mg/packet
Common FDA Label Indication, Dosing, and Titration.
1. Onychomycosis due to dermatophyte: 250 mg po daily × 6 wk for fingernails and × 12 wk for toe nails
2. Tinea capitis: Children <25 kg, 125 mg po daily; Children 25-35 kg, 187.5 mg po daily; Children >35 kg, 250 mg po daily
1. Cutaneous sporotrichosis: 500 mg po bid × 2-4 wk after all lesions have healed
2. Lymphocutaneous sporotrichosis: 500 mg po bid × 2-4 wk after all lesions have healed
MOA. Terbinafine is an allylamine antifungal that inhibits biosynthesis of ergosterol, an essential component of fungal cell membrane. This results in fungal cell death primarily due to the increased membrane permeability. Terbinafine has been shown to be active against most strains of the following microorganisms both in vitro and in clinical infections of Trichophyton mentagrophytes and Trichophyton rubrum.
Drug Characteristics: Terbinafine
Medication Safety Issues: Terbinafine
Drug Interactions: Terbinafine
Adverse Reactions: Terbinafine
Efficacy Monitoring Parameters. Resolution of infection.
Toxicity Monitoring Parameters. Seek medical attention if severe skin reactions occur; if therapy exceeds 6 wk, CBC, liver function tests, etc are warranted.
Key Patient Counseling Points. Instruct patients to report signs/symptoms of rash, infection, or hepatotoxicity. Symptomatic improvement of nail beds may not be seen for several months. Granules should be sprinkled on a spoonful of pudding or other soft, nonacidic food (eg, mashed potatoes) and swallowed without chewing; do not mix granules with applesauce or other fruit-based foods.
Clinical Pearls. Several topical products containing terbinafine, including both prescription and over-the-counter products, are also available for treatment of skin infections.