ARTICLE - Multiple drug interactions with voriconazole in a patient with an increased CYP2C19 activity

Significant interaction of voriconazole and esomperazole, but not ranitidine

27/10/2014 - A 35-year old African female patient with resistant HIV and a cerebral mass of unknown origin was treated with voriconazole for a suspicion of disseminated Aspergillosis infection. Voriconazole trough concentrations (C0) were within target range while the patient was under esomeprazole, a CYP2C19 inhibitor. Phenotyping showed decreased CYP2C19 activity, whereas genotyping showed a variant allele associated with increased enzyme activity. The patient was switched to ranitidine because of the introduction of atazanavir. CYP3A4 inhibition by atazanavir combined with uninhibited CYP2C19 activity resulted in subtherapeutic voriconazole C0. The reintroduction of esomeprazole allowed restoring voriconazole C0 back to target range.

Therapeutic drug monitoring of voriconazole: a case report of multiple drug interactions in a patient with an increased CYP2C19 activity

Bouatou Y, Samer CF, Ing Lorenzini KR, Daali Y, Daou S, Fathi M, Rebsamen M, Desmeules J, Calmy A, Escher M.

AIDS Res Ther. 2014 Aug 4;11:25.

Find this article on Pubmed