Fda Approves Another Powerful New Aids Drug Agency Also Oks New Test To Help Find Blood Donors Newly Infected With Hiv

Merck & Co.’s powerful new AIDS drug, a medicine that wipes out much of the deadly virus in patients’ blood, won government approval Thursday.

Indinavir was approved by the U.S. Food and Drug Administration in a record 42 days - and just two weeks after Abbott Laboratories’ competing ritonavir was cleared.

But indinavir’s rush to the market may pose a dilemma for some patients. Merck is controlling prescriptions for the first six months to ensure it has enough supply, and AIDS patients wonder which of the new medicines will give them the best chance for survival.

“There’s not enough data right now to make a real reasoned choice,” said Gary Rose of the AIDS Action Council.

Also Thursday, the FDA moved to strengthen the safety of the nation’s blood supply, approving a new test to help find blood donors newly infected with HIV, the virus that causes AIDS.

Donors now are tested for an immune reaction to HIV, but it can take up to 25 days after HIV infection for that reaction to occur. Miami-based Coulter Corp.’s antigen test detects the virus itself about six days earlier.

Although getting HIV from a blood transfusion is extremely rare today - about 40 cases out of some 14 million units of blood - closing the testing “window” will prevent five to 10 such infections a year, the FDA said. Blood banks must use the new test by mid-June.

Meanwhile, studies show indinavir, to be sold as the brand Crixivan, virtually can obliterate HIV from the blood cells of many patients.

However, that’s not a cure or even proof that patients will live longer - HIV lurks elsewhere in the body and the small amounts left in the blood can rebound. But studies have shown that the less HIV in the bloodstream, the better the prognosis.

The greatest effect was seen when patients took indinavir together with two standard AIDS medicines, AZT and 3TC. For 90 percent, their HIV levels dropped below 500 particles.

Indinavir is the third in a new class of drugs called protease inhibitors, which work by targeting a different part of HIV than all other AIDS medicines.

It will be available March 25 through a special program. Doctors must prescribe indinavir through Stadtlanders mail-order AIDS pharmacy until Merck’s manufacturing plants are operating fully. Stadtlanders will count indinavir prescriptions to ensure there’s enough supply for everyone to get refills and will limit new patients if a shortage appears.

Doctors generally agree the nation’s first protease inhibitor, Hoffman LaRoche’s saquinavir, is much weaker than the two new ones. But AIDS patients are unsure whether to try indinavir or Abbott’s ritonavir, due to reach pharmacies in days.

Ritonavir cannot be taken with a host of other drugs because it causes dangerous interactions. Indinavir’s main side effect is kidney stones.

AIDS activists say price may make their decision. Indinavir’s wholesale price is about $4,300 a year compared with $6,500 for ritonavir.

Call 800-927-8888 beginning Monday for indinavir information.