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Potential Interaction Between Ritonavir and Carbamazepine
Author(s) -
Kato Yasuhiro,
Fujii Teruhisa,
Mizoguchi Nobuyuki,
Takata Noboru,
Ueda Kazuhiro,
Feldman Mitchell D.,
Kayser Steven R.
Publication year - 2000
Publication title -
pharmacotherapy: the journal of human pharmacology and drug therapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.227
H-Index - 109
eISSN - 1875-9114
pISSN - 0277-0008
DOI - 10.1592/phco.20.9.851.35206
Subject(s) - carbamazepine , ritonavir , cyp3a , pharmacology , cyp3a4 , medicine , anticonvulsant , vomiting , drug interaction , adverse effect , liver function , phenytoin , drug , gastroenterology , epilepsy , cytochrome p450 , virology , viral load , human immunodeficiency virus (hiv) , metabolism , psychiatry , antiretroviral therapy
Ritonavir (RTV), a protease inhibitor, and carbamazepine (CBZ), an anticonvulsant, were administered concurrently to a patient who had human immunodeficiency virus infection and epilepsy. The combination resulted in elevated serum concentrations of CBZ, with accompanying vomiting, vertigo, and transient liver dysfunction. After discontinuing RTV and reducing the dosage of CBZ, the serum concentration of CBZ returned to the optimal range, symptoms subsided, and liver function returned to baseline. Carbamazepine is metabolized in the liver to a large extent by the cytochrome P450 (CYP) system, especially CYP3A4, 2C8, and 1A2, whereas RTV is metabolized primarily by CYP3A and is a potent inhibitor of this enzyme. Careful clinical monitoring may help prevent adverse drug interactions when these drugs are administered concurrently.