HIV Drug

Hard-to-treat AIDS patients will soon have a new option.

The Food and Drug Administration has approved the novel anti-AIDS pill Isentress (EYE'-sen-tris). Its maker, Merck, says it should be on pharmacy shelves within two weeks.

The AIDS virus uses three different enzymes to reproduce and infect cells. Many drugs target two of those enzymes, but Isentress is the first in a new class of medicines that blocks the third.

Merck says the drug, taken twice a day. will cost nearly $9,900 a year -- in the range of other competitors.

Possible side effects include diarrhea, nausea, headache and itching.

(Copyright 2007 by The Associated Press.  All Rights Reserved.)