Federal health officials said Tuesday that asthma drugs, including Merck's Singulair, do not appear tied to suicide — though regulators continue to examine possible links to behavioral problems.
After nine months of review, the Food and Drug Administration said company data do not show any association between the popular respiratory medications and suicide. However, the agency said the studies it reviewed were not designed to detect those events.
"We have finished our analyses of all the data the companies submitted," said FDA spokeswoman Karen Riley. "But that doesn't mean we have closed the book on suicidality."
The FDA said in March it was reviewing a handful of reports involving mood changes, suicidal behavior and suicide in patients who had taken Singulair. The agency launched a probe into the safety of the drug and others in its class, including AstraZeneca PLC's Accolate and Critical Therapeutics Inc.'s Zyflo.
Singulair was Whitehouse Station, N.J.-based Merck's best-selling product last year, with expected sales between $4.3 and $4.5 billion.
After reviewing dozens of company studies, FDA said the drugs do not appear associated with increased risk of suicide.
Regulators said that only one in nearly 10,000 patients taking Singulair in clinical trials reported suicidal tendencies. No patients committed suicide.
FDA's review of Astrazeneca and Critical Therapeutics' uncovered no reports of suicidal tendencies or suicide.
The FDA said in an online statement it would continue reviewing possible associations between mood and behavioral disorders and the drugs, which could take months to complete.
"We will communicate our conclusions and any resulting recommendations to the public at the conclusion of the review," said the agency.
A Merck executive on Tuesday said the company has cooperated with the agency, turning over extensive company records.
"We still believe, after a thorough review of our clinical trial data and post-marketing event reports, that the safety profile of Singulair hasn't changed," said Dr. Scott Korn, vice president for clinical risk management. "We look forward to discussions with the FDA after they've completed their work."
In general, the FDA has begun notifying the public earlier about possible safety issues involving drugs after coming under fire for acting too slowly on information about medicines that were later removed from the market for safety reasons.