Herbal drug products also lead to interactions. St. John's wort can make anti-HIV medication ineffective by lowering the levels of the anti-HIV medication in your blood. Garlic and vitamin C have also been shown to lower these levels. Milk thistle and echinacea can increase levels, leading to more side effects. It's best to avoid herbal products when taking anti-HIV medication, or to talk to your pharmacist before taking them.
|Instructions for Taking Acid-Suppresssing Medications with Anti-HIV Treatments|
|Anti-HIV Medication||Antacids||H2 Blockers||Proton Pump Inhibitors|
|Aptivirus (tipranavir)||Take Aptivirus at least two hours before or one hour after antacid||No information available||No information available|
|Lexiva (fosamprenavir)||Take Lexiva at least two hours before or one hour after antacid||Take Lexiva at least two hours before H2 blocker||No interaction|
|Edurant (rilpivirine); Complera (emtricitabine, rilpivirine, tenofovir, disoproxill fumarate)||Take these anti-HIV medications at least two hours before or four hours after antacid||Take these anti-HIV medications at least 12 hours before or four hours after H2 blocker||DO NOT USE|
|Reyataz (atazanavir) WITHOUT Norvir (ritonavir)||Take Reyataz without Norvir at least two hours before or one hour after antacid||Take Reyataz without Norvir at least two hours before or 10 hours after H2 blocker; No more than Pepcid (famotidine) 20 mg per dose twice a day||DO NOT USE*|
|Reyataz (atazanavir) WITH Norvir (ritonavir)||Take Reyataz with Norvir at least two hours before or one hour after antacid||Take Reyataz with Norvir at same time or 10 hours after H2 blocker; No more than Pepcid (famotidine) 20 mg per dose twice a day**||DO NOT USE|
|*can be used in some cases; ask your pharmacist
**Pepcid (famotidine) dose can be higher in some cases; ask your pharmacist
How can I prevent drug interactions?
There are several important things you can do to prevent drug interactions.
First, filling all your prescriptions at the same pharmacy allows your pharmacist to monitor any possible drug interactions. Whenever your doctor prescribes a new medication, your pharmacist can review all your medications to make sure there are no interactions.
Second, before buying an over-the-counter product, ask your pharmacist whether it will interact with your anti-HIV medication. Your pharmacist may give you special instructions on how to prevent any type of interaction. For example, taking acid suppressants a couple of hours before or after your anti-HIV medication might help prevent interactions. Table 2 gives instructions on how to schedule your acid suppressant medications with certain anti-HIV medications.
Third, it's usually best to avoid herbal products when taking anti-HIV medications, or to speak to your pharmacist for more information.
How can my pharmacist help?