Tummy Trouble? Treat With Caution

So that Halloween candy, Thanksgiving Day feast, or even early batch of Christmas treats at your office have given you a wicked case of heartburn or an upset stomach--and have you reaching for antacids. You should think twice before taking one of these over-the-counter products--or better yet, talk with your doctor before you do--since many antacids interact badly with antiretrovirals. For example, warns Judith Feinberg, MD, former chair of the American Academy of HIV Medicine, over-the-counter antacids (like Alka-Seltzer, Maalox, Mylanta, Tums, and Rolaids) that lower acid levels in the stomach can hamper the body's absorption of protease inhibitors Agenerase, Crixivan, Rescriptor, and Reyataz. They should be taken at least one hour before or after anti-HIV medications--and two hours apart from Reyataz. Likewise, H2 blockers (Axid, Pepcid, Tagamet, Zantac) and proton pump inhibitors (Aciphex, Nexium, Prevacid, Protonix, Prilosec) mix badly with Crixivan, Rescriptor, and Reyataz, says Eric Daar, MD, chief of the Division of HIV Medicine at Harbor-UCLA Medical Center. HIVers on regimens containing any of these drugs should never take proton pump inhibitors, Daar cautions, and use H2 blockers with caution and as far apart as possible from anti-HIV meds--generally at least 12 hours apart. Some caregivers are so concerned about adverse interactions that they recommend patients who are taking Crixivan, Rescriptor, or Reyataz avoid H2 blockers entirely. And Daar adds that Tagamet has unique properties that also make it interact badly with other protease inhibitors'as well as with nonnucleoside drugs. Lexiva, however, appears safe to mix with H2 blockers and proton pump inhibitors, according to pharmaceutical industry studies, says Tom Barrett, MD, an HIV specialist at Chicago's Howard Brown Health Center. Some providers had initially worried about adverse Lexiva-antacid interactions.