Protease inhibitors include amprenavir (Agenerase), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir), and saquinavir (Fortovase, Invirase).
The amino acid glutamine is thought to have protective effects on the digestive tract. One small double-blind study found that use of glycine at 30 grams daily reduced diarrhea caused by nelfinavir. 7
St. John's Wort St. John's wort has been found to decrease blood levels of the HIV drug indinavir by an average of 57%. 1 The reduction is substantial, and could lead to failure of the drug to keep the HIV virus in check. Similar effects are expected to occur with other protease inhibitors. To make matters worse, St. John’s wort also appears to interact with another category of drugs used for HIV, reverse transcriptase inhibitors . The bottom line: If you have HIV, don't take St. John's wort! Furthermore, if you have been stabilized on HIV medications while taking St. John's wort, if you stop taking the herb your blood levels of the drugs could rise, potentially leading to increased side effects.
Grapefruit juice impairs the body's normal breakdown of several drugs, allowing them to build up to potentially excessive levels in the blood. 2 Saquinavir mesylate as well as other protease inhibitors may be affected. A recent study indicates this effect can last for 3 days or more following the last glass of juice. 3Because this could increase the risk of drug side effects, if you take protease inhibitors, the safest approach is to avoid grapefruit juice altogether.