The agency disclosed that its reviewing the safety of AstraZeneca’s Nexium and Prilosec on its web site this morning after the drugmaker last May sent the results of two small, but long-term clinical trials, which suggested use of the drugs may increase the risk of heart attacks or sudden death compared with patients who underwent surgery for acid reflux.

Since then, AstraZeneca has provided FDA more data, including more info on patient follow-up, and pooled analyses of other controlled clinical studies, including placebo-controlled trials of up to two-year’s duration. So far, though, the agency doesn’t see any reason to worry, although a complete review is expected in three months and results will be released at that time. Health Canada, by the way, received the same data and issued a similar statement today.

“At this time, FDA’s preliminary conclusion is that collectively, these data do not suggest an increased risk of heart problems for patients treated with (Prilosec or Nexium). Therefore, FDA does not believe that healthcare providers or patients should change either their prescribing practices or their use of these products at this time,” the FDA notice reads. “…Based on everything we know now, FDA’s preliminary conclusion is that the observed difference in risk of heart attacks and other heart related problems seen in early analyses of the two small long-term studies is not a true effect.”

An AstraZeneca spokesman, meanwhile, e-mailed Pharmalot a statement that, in part, says its “forwarded to all health authorities near complete data from (both) trials, as well as reviewed additional randomized, controlled trial data from over 50,000 patients which collectively show (the drugs) aren’t associated with an increased risk of cardiac events.” (The drugmaker also says all the data is available on its web site).

- there are no differences in the cardiac event reporting rates between the treatment arms in the ongoing Nexium study;

- an older, non-blinded Prilosec study shows an apparent difference in cardiac event reporting rates during the first prior-to-12-months of dosing, a separate evaluation of other controlled clinical trials of 12-24 months duration involving…2,900 patients shows a lower cardiac event reporting rate among Prilosec patients than those given placebo.

Interestingly, the FDA explains that today’s posting, which is described as an “early communication,” is “in keeping with FDA’s commitment to inform the public about its ongoing safety reviews of drugs.” Of course, some FDA critics will say such a move is a step in the right direction - acknowledging safety concerns publicly makes for a more informed medical community. Others, however, will likely say that releasing preliminary results can cause an unnecessary scare for doctors and patients alike, especially if nothing about a safety profile has seemingly changed. In the end, though, more information is usually better.