Gemfibrozil significantly reduced by lopinavir/r

This was an open label, single sequence study in 15 healthy volunteers comparing gemfibrozil pharmacokinetics parameters before and after two weeks of lopinavir/ritonavir (400/100 mg twice daily).

The GMR (90% CI) for gemfibrozil AUC after 14 days of lopinavir/ritonavir compared with base line was 0.59 (0.52 to 0.67) (P<0.001). GMR (90%CI) for gemfibrozil apparent oral clearance and Cmax were 1.69 (1.41 to 1.97) and 0.67 (0.49 to 0.86), respectively (P<0.0001 and P<0.01, respectively). There was no change in gemfibrozil half life.

It is not clear what the mechanism is for the reduction in the systemic exposure of gemfibrozil. However, clinicians treating HIV-infected patients for hypertriglyceridemia should be aware of this interaction.

Ref: Busse KH, Hadigan C, Chairez C, et al. Gemfibrozil concentrations are significantly decreased in the presence of lopinavir-ritonavir. J Acquir Immune Defic Syndr, 2009, 52(2): 235-239.
http://www.ncbi.nlm.nih.gov/pubmed/19648824