(Medical Xpress) -- Treating asthma with leukotriene-modifying agents does not pose an increased risk of suicide in children, according to new research at the University of Illinois at Chicago College of Pharmacy.
UIC professor Glen Schumock began studying the link between suicide and the asthma medications following a U.S. Food and Drug Administration warning in 2008 saying it was reviewing reports of mood and behavior changes and suicidal tendencies among patients taking the drugs.
In a new study published in the Journal of Allergy and Clinical Immunology, Schumock and his research team found no evidence that LTMAs -- an oral treatment that works by blocking inflammation in the airways -- were attributed to suicide attempts.
Two prior studies conducted by Schumock, who also serves as director of UIC's Center for Pharmacoeconomic Research, cast doubts on the increased risk of suicide in those taking LTMAs, but "this was the first objective evidence to refute the association," he said.
The drugs include montelukast, known by its trade name Singulair, one of the 10 most prescribed pharmaceuticals in the U.S.; zafirlukast, marketed as Accolate; and zileuton, or Zyflo. Besides asthma, the drugs are also commonly used for allergic rhinitis.
After reviewing clinical trial data on the LTMA drugs in 2008, the FDA found no suicidal events, but they still issued a warning, Schumock said. Manufacturers were asked by the FDA in June 2009 to include a precaution in the drugs' prescribing information about reports of suicide and other psychiatric problems.
Up until then, the number of LTMA prescriptions dispensed in the U.S. had increased substantially each year. Prescriptions rose from 6.9 million in 1999 to 27.8 million in 2007. However, following the FDA warning in 2008, the number of LTMA prescriptions decreased to 25.8 million, and 25.4 million the following year.
"The drugs could benefit patients, but naturally doctors may have been wary of using them because of the FDA warning," Schumock said. However, the warning was based solely on case reports, which do not prove there is a link between a drug and an adverse event because there can be so many other factors involved, he said.
An insurance claims database was the source of data for Schumock's study. He and his research team found 344 cases of attempted suicide from a group of 195,000 five- to 24-year-olds taking asthma medications.
According to the research, the suicidal group had increased rates of substance abuse, bipolar disease, depression, schizophrenia, and epilepsy, among other illnesses. The subjects also were being treated with additional medications such as antidepressants, antipsychotics, and anticonvulsants. After accounting for these factors, Schumock and his colleagues found no increased risk for suicide among those taking LTMAs compared to other asthma medications.
Among cases, 5.5 percent were using LTMAs at the time of their suicide attempt, compared with 6.5 percent who had not tried to commit suicide. All but five of the subjects were taking montelukast, with the remaining taking zafirlukast. No cases were reported using zileuton, Schumock said.
The research focused on children, adolescents, and young adults. In these patients LTMAs are an important treatment option because these medications can be taken orally, whereas other asthma drugs are inhaled and can be difficult for children to administer, he said.
"While there still needs to be additional research, physicians who treat kids with LTMAs may feel more comfortable now if there was any hesitation before," Schumock said.
Schumock said the research suggested an increased risk of suicide in young adults ages 19 to 24 who used LTMAs, but the finding was not statistically significant. Further research needs to be conducted in that age group and in adults, he said.