Merck & Co Accused of Underplaying Mental Health Risks from Asthma and Allergy Drug Singulair

Initially, when released in 1998, Merck & Co Inc's (NYSE:MRK) asthma and allergy drug, Singulair, claimed side effects were mild and similar to a placebo, and the label stated that its distribution in the brain was "minimal," with no mention of psychiatric side effects.

Over the last two decades, reports suggest that patients, including children, died by suicide or experienced neuropsychiatric issues after taking the drug.

In 2020, the FDA mandated a "black box" warning for Singulair, the most serious warning level, to be included on the drug's label, Reuters reported.

Lawsuits allege that Merck knew from early research that the drug could significantly impact the brain and downplayed the potential for psychiatric problems in statements to regulators.

The lawsuits cite the work of Julia Marschallinger, a cell biologist, who in 2015 found that Singulair's distribution into the brain was more substantial than the label described.

Merck's original patent for Singulair, granted in 1996, indicated potential applications for the drug beyond asthma and allergies, such as a treatment for "cerebral spasm," a neurological condition.

In 1998, an FDA analyst, based on Merck's claims, said that "only a trace amount" of Singulair could be found in the brain.

Marschallinger and her team in Austria conducted their research and reviewed Merck's original research, finding that the drug increased in the brain 24 hours after dosage, contrary to Merck's claims.

Marschallinger suggested the FDA could have asked Merck to conduct more thorough investigations into the drug's brain impacts once reports of mental health issues began to surface.

Disclaimer: This content was partially produced with the help of AI tools and was reviewed and published by Benzinga editors.