The FDA has opened an investigation of anecdotal links between the popular asthma and allergy drug Singulair and suicidal thoughts. In the past year, manufacturer Merck has added warnings of several possible side effects of the pill related to the nervous system, including anxiety, depression, tremors, and suicidal thinking. The FDA says its review of the drug, which had sales of more than $4.3 billion last year, may take up to nine months.
Merck received reports "from physicians, patients and parents or relatives" concerning the drug, which has been used by "millions" of people, said a company official. The review "does not mean that FDA has concluded there is a causal relationship,” said an FDA statement. Related drugs such as Accolate and Zyflo will also be studied for possible links to mood or suicide disorders.