Merck’s & Co.’s asthma drug Singulair and related treatments were not associated with an increased risk of suicide, according to an initial safety review posted by the FDA on its Web site.

 

However, the agency said it is still studying the possibility that Singulair, which is the brand name for the substance montelukast, and other asthma drugs may carry a suicide risk. The agency said it received several suicide reports but a causal relationship between montelukast and suicide has not been established yet. As a result, the FDA asked Merck to investigate the matter and see through further studies if such a link does exist.

 

Risks of tremors, anxiousness, depression and suicidal behavior are already in the drug's label as a result of several updates, but the company said none of the 11,000 patients in their 40 studies committed suicide and the suspicion was triggered by reports only, not studies.

The agency began reviewing safety data on asthma drugs and suicide, suicidal thinking and behaviour and other mood changes in March 2008. The FDA said its review “could take months to complete.”

 

On the other hand, Merck defended its drug, saying that “after horough review of the data from the controlled clinical trials of Singulair, and a careful assessment of post-marketing adverse events, Merck believes that the data support the continued use of Singulair in appropriate patients with asthma and allergic rhinitis.” The drug is available as oral tablets, chewable tablets, and oral granules. In 2007, the company changed Singulair’s prescribing information, the new one including post marketing side effects such as tremors, anxiousness and depression.