This time it's HIV drugs Ziagen, and Videx, two drugs that have now been identified as posing a greater risk for heart attack than other HIV medications.
The manufacturers of the two drugs, GlaxoSmithKline and Bristol-Myers Squibb respectively, have both indicated that a review of clinical trial data reveals no increased risk of heart attack.
However, the US Food and Drug Administration (FDA) is saying today that data pooled from a study of 33,000 HIV patients revealed a greater risk of heart attack associated with taking Ziagen and Videx, than individuals taking other HIV medication.The agency stresses that data is still incomplete, and further scrutiny is required in an effort to verify the heart risk concern. The FDA has said it does not have information from two other drugs in the same class, and therefore can't do a comparison with those.
However, as the FDA appears to be making a greater effort to more proactive, and respond to concerns more quickly than in the past, the emergence of yet another drug, or class of drugs appearing to exhibit difficulties not found in clinical studies begs the question as to the validity of clinical trials in their present form.
Critics of present-day clinical trial protocols suggest that sample rates are too small, and trial windows too short at 12 weeks, the typical window for a pre-market product review.
Others have suggested that trials are designed in such a way as to gain favorable outcomes in an effort to get a drug to market.
The FDA has been criticized for allegedly requiring that in order to approve a new drug for the market, rather than requiring the manufacturer to prove that the drug is safe, data supporting a statement that there is no reason to believe that a drug is not safe, is allegedly all that is required.
There have been several examples of drugs which have demonstrated minimal concern in pre-market trials, only to expose itself as a threat once on the market, and used by a wider cross section of the population. Trasylol, manufactured by Bayer AG, is the perfect example of a drug that showed promise early on, but morphed into a devil once usage levels began to climb.
It has been suggested some drugs are rushed to market so quickly, that in effect the wider population serves as the true, clinical trial.
As for the virus-fighting HIV drugs currently under scrutiny, the FDA is advising doctors to weigh the risks, and the benefits of Ziagen and Videx with their patients while the agency completes its review.