Acetazolamide may provoke cyclosporine toxicity-a case report.

We describe a 58-year-old female renal transplantant recipient with standard cyclosporine-based immunosuppression who developed a potentially toxic cyclosporine concentration of 265 ng/ml after having started acetazolamide for severe glaucoma. The mechanism explaining the interaction between acetazolamide and cyclosporine remains unknown, but the concomitant use of these agents is not uncommon. The follow-up of cyclosporine concentrations is necessary, and the reduction of the cyclosporine dose is likely to be needed when patients taking cyclosporine are started with acetazolamide.