Lamisil Derma (Terbinafine Hydrochloride)

Lamisil Derma (terbinafine) is indicated for superficial fungal infections of the skin caused by dermatophytes.

• Tinea corporis: reduces redness, scaling and itching associated with body ringworm.
• Tinea cruris: alleviates inflammation and itching of the groin area caused by jock itch.
• Tinea pedis: clears the fungal infection of the feet, improving skin integrity and comfort.
• Dermatophytosis: treats a broad range of dermatophyte infections of the skin surface.

• Terbinafine inhibits the fungal enzyme squalene epoxidase, which blocks the conversion of squalene to ergosterol, an essential component of fungal cell membranes. The resulting accumulation of squalene and depletion of ergosterol disrupts membrane integrity, leading to fungal cell death. This mechanism is selective for fungi, allowing topical application to target skin infections with minimal systemic absorption.

Topical terbinafine may cause local skin reactions, ranging from mild irritation to rare severe events.

Common Side Effects

• Burning sensation: mild burning at the application site.
• Itching: transient pruritus around the treated area.
• Redness: localized erythema.
• Dryness: skin dryness or flaking.
• Peeling: mild desquamation of the skin.

Serious or Rare Side Effects

• Severe allergic reaction: swelling, rash, or hives indicating possible hypersensitivity.
• Contact dermatitis: intense inflammation and blistering.
• Stevens‑Johnson syndrome: rare but life‑threatening skin eruption.
• Systemic toxicity: unlikely but possible if large areas are applied, leading to liver enzyme elevation.

When using Lamisil Derma, follow these precautionary measures to ensure safe and effective treatment.

• Apply only to intact skin: avoid broken or inflamed areas to reduce irritation.
• Limit treatment area: do not exceed the recommended surface area without medical advice.
• Avoid occlusion: do not cover the treated skin with airtight dressings unless directed.
• Monitor for allergic response: discontinue use and seek medical attention if rash or swelling develops.
• Use as directed by healthcare professional: follow prescribed frequency and duration.
• Store at room temperature: keep below 25 °C, protect from moisture and direct sunlight in the original container.

Topical terbinafine has a low potential for systemic drug interactions, but certain substances may affect its safety or efficacy.

Major Interactions (Avoid)

• Systemic antifungals (e.g., itraconazole, fluconazole): concurrent systemic use may increase risk of hepatotoxicity.
• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine): may raise systemic terbinafine levels if large skin areas are treated.
• Alcoholic beverages: excessive intake can exacerbate potential liver effects.

Moderate Interactions (Monitor Closely)

• Topical corticosteroids: may reduce antifungal effectiveness when used on the same site.
• Warfarin: monitor INR if extensive skin areas are treated, as terbinafine can affect metabolism.
• Hormonal contraceptives: observe for reduced efficacy when large areas are applied over prolonged periods.