Voriconazole

Broad-spectrum triazole antifungal with excellent corneal penetration for equine keratomycosis (Fusarium, Aspergillus) and systemic fungal infections. Second-generation triazole antifungal (voriconazole). Mechanism: inhibits fungal CYP51 (lanosterol 14α-demethylase) → blocks ergosterol synthesis → disrupts fungal cell membrane. Broader spectrum than fluconazole — active against Aspergillus, Fusarium, and fluconazole-resistant Candida. Highly lipophilic; excellent tissue penetration including cornea in horses. IV or oral administration. Key information Antifungal — horses (especially aspergillosis). Oral bioavailability excellent. Significant drug interactions (CYP2C19, CYP3A4 inhibitor). Monitor hepatic function. Store at room temperature. Visual disturbances reported in humans — monitor for behavioral changes.

Oral tablets: Administer orally. May be given with food to improve compliance and reduce GI upset. Administer on an empty stomach for optimal absorption. for best absorption. Separate from antacids by 1 hr. IV (extra-label): dilute in 0.9% NaCl; infuse over 1–3 hrs. Ophthalmic (compounded, horses): instill into conjunctival sac 4–6 times daily. Minimize horse's UV exposure during treatment. Store at room temperature; protect from light. If a dose is missed Administer as soon as you remember. If it is almost time for the next scheduled dose, skip the missed dose and resume the normal schedule. Never double up doses to make up for a missed one. Complete the full antifungal course.

GI: vomiting, anorexia, diarrhea. Photosensitivity reactions in horses (UV-mediated — skin ulceration/squamous cell carcinoma risk with prolonged high-dose use — limit UV exposure, apply sunscreen). Hepatotoxicity (monitor liver enzymes). CNS: visual disturbances (fluoride neurological effects). QT prolongation. Numerous drug interactions.

For animals Horses: photosensitivity — limit UV exposure; squamous cell carcinoma of unpigmented skin reported with prolonged use. Monitor liver enzymes with prolonged use. Monitor renal function, hydration status, and urine output. Numerous CYP drug interactions — review concurrent medications. Avoid in pregnant animals. For people handling this medication Wear gloves when handling. Wash hands thoroughly with soap and water after handling. Triazole antifungal — Keep out of reach of children. Pregnant women and women of childbearing age should avoid contact. Teratogenic. Wear gloves. Photosensitivity — use sun protection. Numerous drug interactions — inform your doctor.

Contact your veterinarian. Overdose causes liver toxicity, visual disturbances, and GI signs. Liver monitoring required. Contact your veterinarian, a veterinary emergency clinic, or the ASPCA Animal Poison Control Center (888-426-4435) immediately. Do not induce vomiting unless specifically directed by a veterinary professional.