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Case Reports
. 2007 Aug 14;177(4):357-9.
doi: 10.1503/cmaj.061284.

Interaction between lopinavir/ritonavir and warfarin

Christine A Hughes  1 , Andrea Freitas, Lilly J Miedzinski
Affiliations
Case Reports

Interaction between lopinavir/ritonavir and warfarin

Christine A Hughes et al. CMAJ. .

Abstract

Drug interactions involving protease inhibitors are common. Protease inhibitors are well known inhibitors of the 3A4 isozyme of cytochrome P450. Select protease inhibitors, including co-formulated lopinavir/ritonavir, may induce glucuronidation or the activity of other CYP450 isozymes. We describe the case of a patient taking warfarin who experienced a significantly decreased international normalized ratio after the initiation of antiretroviral therapy that included lopinavir/ritonavir. We review the possible mechanisms of this interaction and the reported interactions between warfarin and other protease inhibitors.

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References

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