Up to 24 million asthma and allergy patients, including children as young as 12 months, are potentially risking serious mental health side effects from taking Singulair tablets and granule packets manufactured by Merck & Co.
Montelukast, the active ingredient in Singulair, blocks substances in the body called leukotrienes to help improve symptoms of asthma and allergic rhinitis. According to the FDA, side effects of Montelukast, include suicidal thoughts and actions, as well as behavior or mood-related changes like:
• Agitation, including aggressive behavior or hostility
• Attention problems
• Bad or vivid dreams
• Disorientation or confusion
• Feeling anxious
• Hallucinations (seeing or hearing things that are not really there)
• Memory problems
• Obsessive-compulsive symptoms
• Tremor or shakiness
• Trouble sleeping
• Uncontrolled muscle movements
The FDA identified cases of completed suicides associated with Montelukast, with many reporting the development of neuropsychiatric symptoms prior to the suicide. The side effects can happen to people with and without mental disorders. Some patients had the effects continue even after they stopped taking the drug.
The FDA required a black box warning – the agency’s most prominent warning – in March 2020 to strengthen an existing warning about the risk of neuropsychiatric events associated with the drug. The FDA said that many health care professionals and patients are not aware of the risk.
“We recognize that millions of Americans suffer from asthma or allergies and rely on medication to treat these conditions. The incidence of neuropsychiatric events associated with montelukast is unknown, but some reports are serious, and many patients and health care professionals are not fully aware of these risks,” said Sally Seymour, M.D., director of the Division of Pulmonary, Allergy and Rheumatology Products in the FDA’s Center for Drug Evaluation and Research.
“The FDA aims to make sure patients and medical providers have the information available to make informed treatment decisions. Importantly, there are many other safe and effective medications to treat allergies with an extensive history of use and safety, such that many products are available over the counter without a prescription.”
Immediate Adverse Events
The prescription drug generated $698 million in sales for Merck in 2019. In 2018, approximately 9.3 million patients of any age received a prescription for Montelukast from US retail pharmacies. Of these, approximately 2.3 million were children younger than 17 years.
Mass tort law firms are actively reviewing potential claims on behalf of patients who used Singulair and suffered an unwarned adverse event. No MDL has been created yet.
The FDA approved prescription Montelukast in 1998 to treat asthma for children and adults, for seasonal allergic rhinitis in 2002, for perennial rhinitis in 2005, and for exercise-induced bronchoconstriction in 2007.
Montelukast is used to prevent wheezing, difficulty breathing, chest tightness and coughing caused by asthma, and also to treat sneezing and stuffy, runny or itchy nose from hay fever.
However, the FDA started getting adverse event reports for in 2008, primarily for depression, aggression, irritability, nightmares, insomnia, and suicidality. The suicide of a 15-year-old boy taking Montelukast in 2007 was one event prompting the FDA review.
The FDA updated its Singulair labeling include a precaution against neuropsychiatric events in 2008.
The market for Singulair is huge. Allergies and hay fever affect as much as 30% of US adults – between 30 million and 60 million people, according to Public Citizen.
In 2014, Merck asked for FDA approval for over-the-counter sales for adults and only for the treatment of allergy symptoms. Public Citizen successfully asserted that Singulair was too dangerous to be sold over the counter because it has minimal benefits but posed potentially serious health risks. The FDA banned the proposed Singulair OTC sales on May 2, 2014.
The FDA reevaluated the risks and benefits of Montelukast and determined it should not be the first choice treatment particularly when allergic rhinitis symptoms.