Lamisil (Terbinafine Hydrochloride)

Lamisil is an allylamine antifungal indicated for several superficial dermatophyte infections.

• Tinea pedis (athlete's foot): reduces fungal growth, relieving itching, scaling and redness.
• Tinea corporis (ringworm): clears the infection and promotes healing of skin lesions.
• Tinea cruris (jock itch): diminishes fungal proliferation and eases discomfort in the groin area.
• Tinea versicolor: normalizes skin pigmentation by eliminating the yeast responsible.
• Superficial dermatophyte infections: eradicates the causative fungi and restores normal skin integrity.

• Terbinafine inhibits fungal squalene epoxidase, an enzyme essential for ergosterol synthesis. This inhibition leads to accumulation of squalene and depletion of ergosterol, disrupting the fungal cell membrane structure and function, ultimately causing fungal cell death and clearance of the infection.

Lamisil is generally well tolerated, but some users may experience adverse reactions.

Common Side Effects

• Local skin irritation: redness, burning or stinging at the application site.
• Pruritus: mild itching of the treated area.
• Dryness: skin may become dry or flaky.
• Erythema: mild redness without infection.
• Contact dermatitis: allergic skin reaction in sensitive individuals.

Serious or Rare Side Effects

• Severe allergic reaction: swelling, hives, or difficulty breathing.
• Hepatotoxicity: signs of liver dysfunction such as jaundice or dark urine.
• Stevens‑Johnson syndrome: severe skin blistering and mucosal involvement.
• Blood disorders: unexplained bruising or bleeding.
• Persistent irritation: worsening redness or ulceration at the site.

Before using Lamisil, consider the following safety measures.

• Allergy assessment: avoid if known hypersensitivity to terbinafine or formulation components.
• Liver function: use caution in patients with existing liver disease; monitor hepatic enzymes if prolonged therapy is required.
• Pregnancy and lactation: discuss potential risks with a healthcare professional before use.
• Pediatric use: limit to ages and conditions approved by local regulatory authorities.
• Application area: apply only to intact skin, avoiding eyes, mucous membranes and open wounds.
• Store at room temperature: keep in the original container, protect from moisture and heat.

Terbinafine may interact with other medications, requiring attention to potential effects.

Major Interactions (Avoid)

• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine): may increase terbinafine plasma levels.
• Warfarin: concurrent use may enhance anticoagulant effect, increasing bleeding risk.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce terbinafine effectiveness.
• Other antifungals (e.g., itraconazole): combined use may increase toxicity.
• Alcohol: excessive intake may exacerbate liver strain during therapy.