TERBINAFINE HYDROCHLORIDE

(ter-bin'a-feen)

Lamisil, Lamisil DermaGel
Classifications: antibiotic; allylamine antifungal;
Therapeutic: antibiotic; antifungal
Pregnancy Category: B

Availability

250 mg tablets; 1% cream; 1.12% gel

Action

Synthetic antifungal agent that inhibits sterol biosynthesis in fungi and ultimately causes fungal cell death.

Therapeutic Effect

Effective as a topical antifungal treatment as well as in oral form.

Uses

Topical treatment of superficial mycoses such as interdigital tinea pedis, tinea cruris, and tinea corporis due to Epidermophyton floccosum, Trichophyton mentagrophytes, or T. rubrum; oral treatment of onychomycosis due to tinea unguium.

Contraindications

Hypersensitivity to terbinafine; alcoholism; hepatic disease; hepatitis; jaundice; renal impairment; renal failure; lactation.

Cautious Use

Pregnancy (category B). Safety and efficacy in children <12 y are not established.

Route & Dosage

Tinea Pedis, Tinea Cruris, or Tinea Corporis
Adult: Topical Apply q.d. or b.i.d. to affected and immediately surrounding areas until clinical signs and symptoms are significantly improved (1–7 wk)

Onychomycosis
Adult: PO 250 mg q.d. x 6 wk for fingernails or x 12 wk for toenails

Administration

Topical

Apply externally. Avoid application to mucous membranes and avoid contact with eyes.
Do not use occlusive dressings unless specifically directed to do so by physician.
Store at 15°–30° C (59°–86° F).

Adverse Effects (≥1%)

Skin: Pruritus, local burning, dryness, rash, vesiculation, redness, contact dermatitis at application site. CNS: Headache. GI: Diarrhea, dyspepsia, abdominal pain, liver test abnormalities, liver failure (rare). Hematologic: Neutropenia (rare). Special Senses: Taste disturbances.

Interactions

Drug: May increase theophylline levels; may decrease cyclosporine levels; rifampin may decrease terbinafine levels.

Pharmacokinetics

Absorption: 70% PO; approximately 3.5% of topical dose is absorbed systemically. Elimination: In urine. Half-Life: 36 h.

Nursing Implications

Assessment & Drug Effects

Monitor for and report increased skin irritation.

Patient & Family Education

Learn correct technique for application of cream.
Notify physician if drug causes increased skin irritation or sensitivity.
Be aware that medication must be used for full treatment time to be effective.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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