HIV Digest	HIV Digest Archive

The protease inhibitor amprenavir (Agenerase) has been approved for marketing by the FDA. This approval was based on two 24-week controlled trials in adults, plus safety data in over 1,400 patients, under the FDA's accelerated-approval regulations.

Amprenavir is taken twice a day, with or without food, but it should not be taken with a high-fat meal, as that would decrease the absorption of the drug.

The most common side effects are gastrointestinal (nausea, vomiting, and/or diarrhea), rashes, and oral paresthesia (a tingling sensation around the mouth). Patients should know that severe or life-threatening rash has occurred is 1% of recipients (4% of those who develop a rash), and that "amprenavir therapy should be discontinued for severe or life-threatening rashes and for moderate rashes accompanied by systemic symptoms" (quoted from the FDA's official labeling of the drug). Several prescription drugs must not be taken with amprenavir, and several others require blood tests to monitor drug levels. Patients should receive written information about amprenavir, including these and other precautions, from their physician or pharmacist.

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Studies of lipid biochemistry have suggested that amprenavir may be less likely than other protease inhibitors to be associated with certain problems of lipid metabolism. No one knows today whether there will be a practical difference for patients, since these problems became prominent only after protease inhibitors had been used for some time.

Amprenavir may have a different resistance profile from other protease inhibitors-- which might or might not mean less problem with cross resistance. But it is not known at this time how much persons who have become resistant to other protease inhibitors could benefit from amprenavir-- or conversely, whether those who start with amprenavir and become resistant to it can use the other protease inhibitors effectively.

In laboratory tests, amprenavir appears to be synergistic with abacavir (Ziagen), another Glaxo drug, meaning that they might work well together. But there is a practical problem with the combination, especially if the two drugs are started at about the same time-- for if a serious drug reaction occurs and both drugs must be stopped, there may not be any way to determine which of them caused the problem.

Editor's Note: from AIDS Treatment News