FDA studies a possible link between drugs and mental disorders.

You don’t normally associate asthma with suicide.

But asthma-treatment drugs like Singulair have been identified by the FDA for reported cases of “agitation, aggression, anxiousness, dream abnormalities and hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior [including suicide], and tremor.”

Mental Disorders Reported

The FDA on June 12 asked that the makers of a class of asthma drugs called leukotriene receptor agonists place a precaution on the drugs’ labels to warn of the potential for what the agency calls neuropsychiatric events -- mental disorders attributable to diseases of the nervous system, Forbes reported.

The FDA recommends that:

            • Patients and healthcare professionals should be aware of the potential for neuropsychiatric events with these medications;

            • Patients should talk with their healthcare providers if these events occur; and

            • Healthcare professionals should consider discontinuing these medications if patients develop neuropsychiatric symptoms.

Blockbuster Drug Cited

The drugs in question include the blockbuster medication Singulair, Accolate, Zyflo, and Zyflo CR -- drugs in a class known as leukotriene synthesis inhibitors. Leukotriene receptor antagonists target part of the body’s inflammatory process. They are prescribed to treat asthma and the symptoms of allergic rhinitis, and to prevent exercise-induced asthma.

Approved by the FDA in 1998 to treat asthma and allergies in children and adults, Singulair is a big money-maker for pharmacy giant Merck; it earned Merck $4.3 billion in sales in 2008, according to attorneyatlaw.com.

The FDA said patients taking these medications should be aware of the potential hazard and talk to their doctors if some sort of neuropsychiatric problem occurs. Doctors may then decide to discontinue the medication, the agency said.

No Such Evidence, At First

The move follows an ongoing FDA safety review of possible suicidal behavior among those taking asthma drugs, Forbes reported. In early January, FDA officials said they had found no evidence of a link.

In the clinical trial data submitted by manufacturers, neuropsychiatric events were not commonly observed, FDA officials said. But those trials were not designed to look for mental disorders attributable to diseases of the nervous system. “Sleep disorders were reported more frequently with all three products compared to placebo,” the agency said.