[Cushing's syndrome induced by combined treatment with inhaled fluticasone and oral ritonavir]. / Syndrome de Cushing induit par la prise concomitante de fluticasone et de ritonavir.

ABSTRACT

INTRODUCTION: Fluticasone is a corticosteroid drug which is used in inhaled and nasal formulations for the treatment of asthma and allergic rhinitis. It is metabolized in the liver by the cytochrome P450. Ritonavir, an inhibitor of the HIV protease, also acts as an inhibitor of several isoenzymes of the P450 cytochrome. This property explains the many drug interactions observed with this agent. CASE REPORT We report two cases of Cushing's syndrome with adrenal insufficiency associated with the combined administration of oral low dose ritonavir and moderate to high dose inhaled fluticasone. CONCLUSION: These observations highlight the fact that the combined administration of fluticasone and ritonavir must be avoided as well as the combined administration of fluticasone and other inhibitors of the cytochrome P450.