Acid reducing agents and protese inhibitors

1 December 2007. Related: PK and drug interactions.

HIV-druginteractions.org

There have been two publications in October’s HIV Medicine on this important topic.

Beique et al have provided a systematic review of all the available pharmacokinetic and clinical data on drug interactions between protease inhibitors and acid-reducing agents and their clinical consequences. The table documenting the interactions is a particularly valuable resource. [1]

However, new data are constantly emerging and Luber et al have documented their findings on once daily fosamprenavir/ritonavir and atazanavir/ritonavir alone and in combination with 20 mg omeprazole in healthy volunteers.

This paper is an update of reference 12 cited by Beique et al – data initially presented at the Lisbon HIV Pharmacology Workshop in 2006. The major findings were:

• No impact of omeprazole on amprenavir exposure.
• Atazanavir AUC and Cmin reduced by 27%.
• 4/19 subjects experienced greater than 50% decline in both AUC and Cmin.

References:

1. Beique L, Giguere P, la Porte C, Angel J. Interactions between protease inhibitors and acid-reducing agents: a systematic review. HIV Med, 2007, 8(6):335-345.
2. Luber A, Brower R, Kim D, et al. Steady-state pharmacokinetics of once-daily fosamprenavir/ritonavir and atazanavir/ritonavir alone and in combination with 20 mg omeprazole in healthy volunteers. HIV Med, 2007, 8(7):457-464.