Myconafine (Terbinafine Hydrochloride)

Terbinafine Hydrochloride is an allylamine antifungal indicated for the topical treatment of common superficial dermatophyte infections affecting the skin.

• Tinea pedis (athlete’s foot): reduces itching, scaling and erythema while eradicating the dermatophyte on the feet.
• Tinea corporis (ringworm): eliminates the characteristic ring‑shaped lesions and restores normal skin appearance on the trunk or limbs.
• Tinea cruris (jock itch): clears fungal growth in the groin and inner thigh, relieving irritation and redness.

• Terbinafine Hydrochloride inhibits the fungal enzyme squalene epoxidase, a key step in the biosynthesis of ergosterol, the principal sterol of fungal cell membranes. Blockade of this pathway leads to accumulation of squalene, which is toxic to the fungus, and depletion of ergosterol, disrupting membrane integrity and causing fungal cell death. The selective inhibition spares human cells because humans do not rely on ergosterol for membrane structure.

Topical terbinafine may cause local skin reactions and, rarely, systemic adverse events.

Common Side Effects

• Itching: mild to moderate sensation at the application site.
• Burning: transient heat sensation during early treatment.
• Redness: localized erythema around the treated area.
• Scaling: flaking of skin as infection resolves.
• Dryness: temporary loss of skin moisture.
• Irritation: mild discomfort or stinging.

Serious or Rare Side Effects

• Severe allergic reaction: hives, swelling, or difficulty breathing.
• Stevens‑Johnson syndrome: rare severe skin blistering requiring medical attention.
• Hepatic toxicity: abnormal liver function tests in systemic absorption cases.
• Contact dermatitis: intense rash extending beyond application site.

When using Myconafine, consider the following precautions to ensure safe and effective treatment.

• Assess liver function: evaluate baseline hepatic status in patients with liver disease.
• Avoid use on broken skin: do not apply to open wounds or ulcerated areas.
• Limit application area: restrict to affected sites and avoid excessive coverage.
• Monitor for hypersensitivity: discontinue if signs of allergic reaction appear.
• Use with caution in children: follow pediatric guidance and monitor for irritation.
• Store at room temperature: keep in the original packaging, protect from moisture and direct sunlight.

Terbinafine may interact with other medicines; awareness of major and moderate interactions helps prevent adverse outcomes.

Major Interactions (Avoid)

• Itraconazole: combined use increases risk of hepatotoxicity.
• Cimetidine: may raise terbinafine plasma concentrations.
• Strong CYP2D6 inhibitors: can elevate terbinafine levels, enhancing toxicity.

Moderate Interactions (Monitor Closely)

• Alcohol: concurrent consumption may stress liver function.
• Warfarin: monitor INR as terbinafine may affect anticoagulant effect.
• Other topical agents: simultaneous use may increase skin irritation.