The Food and Drug Administration (FDA) is busy analyzing data from an ongoing study tracking the cardiovascular risks associated with two important HIV Drugs called Videx and Ziagen. The FDA is reviewing data from a large study known as the DAD study, which is thought to be the largest study of its kind ever undertaken. DAD tracks HIV patients on three continents - patients who are being treated with a variety of anti-HIV drugs.

Preliminary data review suggests that both Videx and Ziagen carry an increase in the risk of cardiovascular events - specifically, heart attack. That means that patients taking one of these two drugs may be more likely to have a heart attack compared to patients being treated with other anti-HIV drugs. Notably, the FDA review shows that the increase in risk appears to be sudden and reversible. That means that the risk rises as soon as one begins treatment, rises to an absolute and predictable level where it stays for the duration of treatment, and goes away when the drug is stopped.

The makers of both drugs, as well as the FDA, stress that all of the data has yet to be gathered, and that the review is still incomplete. Drug makers stress that while the increase in risk might be real, the actual overall risk is still very small. In other words, one must weigh the risks and benefits. If a drug is very effective at treating a disease, but increases the risk of heart attack from (for example) 1 in a million to 5 in a million, it's still a good drug. While it is technically correct to say that the drug raises the risk of heart attack by 500%, the actual risk of having a heart attack while on the drug is still small.

Data review is ongoing, and no official recommendations have been issued.