Voriconazole: reminder of risk of liver toxicity, phototoxicity, and squamous cell carcinoma

MHRA Drug Safety Update May 2014

Advice for healthcare professionals:

The advice below applies to both adults and children taking voriconazole.

Liver toxicity

• Test liver function before starting treatment with voriconazole (specifically, aspartate transaminase [AST] and alanine transaminase [ALT] levels).
• Continue testing liver function at least weekly for the first month of treatment and monthly thereafter if there are no changes in the first month of treatment.
• Stop voriconazole if AST or ALT levels become markedly elevated, unless you consider the benefits of voriconazole treatment to outweigh the risk of liver toxicity in that individual.

Phototoxicity and squamous cell carcinoma

• Tell patients to avoid sunlight exposure while taking voriconazole. Advise patients to wear protective clothing and use sunscreen with a high sun protection factor if in sunlight.
• Refer patients with phototoxic reactions to a dermatologist and consider stopping voriconazole treatment.
• If voriconazole is continued despite a phototoxic reaction, check the skin frequently and thoroughly to detect and manage pre-cancerous lesions as early as possible.
• Stop voriconazole if pre-cancerous skin lesions or squamous cell carcinoma are identified. Note that patients may develop squamous cell carcinoma without a prior phototoxic reaction.