More on Interactions between Darunavir and Pravastatin: To Use or Not to Use?
May 18, 2012
Recommendations for coadministration of pravastatin with darunavir have been based on a small PK study that showed substantial intersubject variability in the impact of interactions between the two drugs. In that study, concurrent administration of pravastatin (40 mg, single dose) with darunavir/ritonavir 600 mg/100 mg BID resulted in an overall geometric mean increase in pravastatin AUC of 81% and Cmax of 63%, compared with levels when pravastatin was taken alone. Further, in a few study subjects, the pravastatin AUC and Cmax increases were even higher (for AUC, up to 6 times higher than baseline, for Cmax, up to 10 times higher).
A recently published study examined these same drug interactions. In that study, 40 mg of pravastatin was administered to 28 healthy volunteers before and after starting darunavir/ritonavir 600 mg/100 mg BID. In the overall study population, the geometric mean increase in pravastatin AUC was 21% and the increase in Cmax was 23%, when compared with baseline measures. As in the first study, though, some subjects had much larger increases in pravastatin levels (up to a 4-fold increase in AUC) when this statin was given concurrently with darunavir/ritonavir.
Clinical Bottom Line
Although the second study shows a lesser overall effect of darunavir/ritonavir on pravastatin levels, it confirms that some individuals experience a huge and potentially dangerous increase in levels of this statin. Based on these data, clinicians should continue to follow the recommendations presented in the darunavir package insert: When pravastatin is used with darunavir, it should be started at the lowest dosage with careful monitoring for toxicity. The darunavir package insert further states that atorvastatin dosage should not exceed 20 mg per day.
- Sekar VJ, Spinosa-Guzman S, Marien K, et al. Pharmacokinetic drug-drug interaction between the new HIV protease inhibitor darunavir (TMC114) and the lipid-lowering agent pravastatin. In: Program and abstracts of the 8th International Workshop on Pharmacology of HIV Therapy; April 16-18, 2007; Budapest. Abstract 54.
- 2. Aquilante CL, Kiser JJ, Anderson PL, et al. Influence of SLCO1B1 polymorphisms on the drug-drug interaction between darunavir/ritonavir and pravastatin. J Clin Pharmacol. 2011 Dec 14. [e-pub ahead of print]
Susa Coffey is medical editor of the NCRC. She is a Professor of Medicine at UCSF in the Division of HIV, Infectious Diseases and Global Medicine and a longtime clinician and educator in the HIV at San Francisco General Hospital clinic (“Ward 86”). She also is medical editor of HIV InSite.