Rifabutin reduces
posaconazole levels by about 50% and
posaconazole increases the AUC of
rifabutin. Uveitis has been attributed to the concurrent use of these drugs.
Concurrent use should be avoided unless the benefits are expected to outweigh the risks. If used together, the
efficacy of
posaconazole and
toxicity of
rifabutin should both be closely monitored, particularly full blood counts and uveitis.