I have been on amlopidine/Norvasc (10mg once per day) for several years. Three weeks ago, my HIV doctor switched my HIV regimen to Reyataz+Norvir+Truvada. The doctor called me today to say that amlopidine is in a category of drugs that may interact adversely with Reyataz and/or Norvir and that I should discuss this with my primary doctor. Can you tell me what the adverse interaction is and whether I should stop taking the amlopidine until I can get an appointment with my primary doctor?

Amlodipine (Norvasc) is a calcium channel blocker which is primarily used to treat high blood pressure. Norvir and Reyataz are protease inhibitors and this class of agents, especially Norvir, may slow down the metabolism of calcium channel blockers and lead to an enhanced effect of these medications. That said, in clinical practice protease inhibitors are used together with calcium channel blockers and generally there is no problem. But this potential interaction should be monitored, and if someone on Norvasc develops low blood pressure after the addition of a protease inhibitor then this would need to be addressed by either stopping the medication or reducing the dose.

Thanks for posting and good luck!