Maker of popular allergy drug not required to study long-term mental health impact

An Arizona mother said hearing about our investigation led her to make the connection between...
An Arizona mother said hearing about our investigation led her to make the connection between the drug's side effects and her daughter's behavior.(Arizona's Family)
Updated: Nov. 3, 2021 at 4:34 PM MST
Email This Link
Share on Pinterest
Share on LinkedIn

This is part two of investigations into Singulair and expands our coverage on the drug’s potential long-term side effects. Part One details the drug’s potential mental health side effects, evidence the manufacturer had information the drug affected the brain before it was marketed as an allergy asthma medication, and lack of studies on long-term effects.

PHOENIX (3TV/CBS 5) - Parents are being put in a difficult position, wanting to speak out and warn other families about the mental health side effects their children suffered on Singulair or its generic form, while at the same time protecting their children’s privacy.

A mother told Arizona’s Family that she had no idea what triggered her daughter’s mental health issues until she saw our investigation profiling Tyson Pany and his mother, Kammy in February 2021. She said at that moment a lightbulb went on. Hearing about Tyson’s side effects and the mental health issues suffered by other children led her to make the connection between the drug’s side effects and her daughter’s behavior.

A doctor prescribed had prescribed her 11-year-old Montelukast, the generic version of Singulair. Over the next few years, she said her outgoing star student became withdrawn, antisocial, depressed, developed tics and OCD, and started having hallucinations. “She would wake up in the middle of the night screaming that there were bugs on her. We actually had to get her into therapy. We thought she was going crazy. It was really scary.”

After three years of doctors not connecting the symptoms to the medication, doctors doubled her daughter’s dose of Montelukast. She said her daughter’s symptoms got worse. That’s when they decided to stop giving their daughter Montelukast altogether. Some symptoms improved. For example, a tic she developed of blowing on her hands began going away, but months after stopping the medication, she’s still suffering from bouts of anxiety and depression. “The scariest thing in my opinion is that there is not a lot out there and a lot of people don’t know how much damage this can do to children,” says her mother.

But how much damage is being done?

The question of whether or not the drug permanently alters the brain is an ongoing concern among members of the Facebook group Montelukast (Singulair) Side Effects Support and Discussion.

Investigative reporter Kris Pickel checked in with Kammy and Tyson recently, nearly a year after her first interview with them. Kammy said Tyson’s symptoms improved dramatically in the year after stopping Montelukast. However, it’s been four years since Tyson stopped taking the drug and he still suffers from lingering side effects including extreme chemical sensitivity to medications, artificial additives, dyes, and sweeteners in foods. She said it’s common to hear similar concerns among members of the Facebook group. Tyson is on a restricted diet. The ingredients are checked on everything he eats but when a mistake is made and something slips by, the consequences are severe.

“His pupils get huge and sometimes he’ll cry. You can’t console him.” Kammy explained a recent episode after Tyson ate a snack bar, “I thought I checked all the ingredients but within 10 minutes he was bashing his head into the wall. I lost him for a day.” Tyson said when the episodes happen, he has a hard time remembering them but tried to explain what is going on in his mind, “I just get really mad and kind of lose control. It’s kind of crazy to see and it’s not fun for anyone when it happens.”

Box Warning Issued in March 2020

The FDA issued a ‘box warning’ for Singulair and its generic Montelukast in March of 2020. A box warning is the agency’s strongest warning and alerts patients a drug carries the potential for serious side effects or death.

Included in the FDA’s warning:

  • Serious mental health side effects have been reported in patients taking Singulair.
  • Because of the risk of mental health side effects, the benefits of Montelukast may not outweigh the risk in some patients.
  • Singulair should be reserved to treat allergies only in patients who cannot tolerate other medicines.
  • Discontinue Singulair immediately if mental health side effects occur.

Effects on the brain

When the FDA approved Singulair in 1998, it did not require Merck to conduct further studies of the drug’s effects on the brain, despite Merck submitting studies detailing the drug passed through the blood-brain barrier in rats. The barrier is a membrane that blocks harmful substances from entering the brain.

In 2019, the FDA held a public meeting on the mental health side effects of Montelukast in children. A doctor with the FDA acknowledged, while the FDA had the authority to request more studies by the manufacturer, they would most likely not be able to force Merck to do the studies. If the FDA required Merck to conduct additional studies on safety, which are expensive, Merck could let their New Drug Application (NDA) expire. That move would leave only generic versions on the market. The FDA cannot force companies who make generic versions of drugs to do studies.

While the FDA is not requiring any additional studies by Merck, according to an FDA spokesperson, there is currently an internally-funded research project at the National Center for Toxicological Research (NCRH), a branch of the FDA. The study will “investigate potential central nervous system toxicity with montelukast in animal models,” according to FDA spokesperson Chanapa Tantibanchacha.

Attempts to contact the study organizer for details on the scope of the study were diverted back to the FDA which provided the study description as: “The NCTR has initiated studies with montelukast to evaluate for potential neurological targets that may be linked to adverse neuropsychiatric events and to evaluate the spatial (3-D) distribution of drug, drug metabolites, and neurotransmitters.” Tantibanchacha was not able to confirm if long-term effects on the brain will be included in the study.

Parents aren’t giving up

Kammy and the mother who asked not to be identified are among the families speaking out in hopes of getting a doctor interested in studying the drug’s long-term effects on the brain. They say no one in the medical profession has yet to show any interest in taking on the research.