Itrasys 400 Capsule contains Itraconazole 400 mg, a broad-spectrum antifungal agent belonging to the triazole class. It is indicated for the treatment of various systemic and superficial fungal infections, including aspergillosis, blastomycosis, histoplasmosis, onychomycosis, and candidiasis. Itraconazole exerts its antifungal effect by inhibiting the cytochrome P450-dependent enzyme lanosterol 14-α-demethylase, which is essential for ergosterol synthesis in fungal cell membranes. This disruption leads to increased membrane permeability and ultimately fungal cell death. Itrasys 400 Capsule is administered orally and demonstrates good bioavailability, with enhanced absorption when taken with food. The drug is extensively metabolized in the liver and has a half-life of approximately 24 to 42 hours, allowing for convenient dosing schedules. Caution is advised in patients with hepatic impairment or congestive heart failure, as itraconazole may exacerbate these conditions. Common adverse effects include gastrointestinal disturbances, headache, and rash, while rare but serious effects may involve hepatotoxicity and cardiac issues. Itrasys 400 Capsule should be used under medical supervision, with monitoring of liver function and potential drug interactions due to its influence on cytochrome P450 enzymes.