The drug Singulair is now subject to “strong warnings and precautions” by Health Canada, the strongest type of warning that exists in the country. Many patients are still prescribed this medication, often when other asthma treatments fail. Even in Quebec.
The DD Francine Ducharme, pediatrician and clinical epidemiologist at CHU Sainte-Justine, regularly meets patients who experience severe side effects from the drug. “I have them at least every two weeks. »
Agitation, aggression, depression, sleep problems, suicidal thoughts and behavior: the DD Ducharme saw them all.
One of her patients started taking the drug Singulair at age 5. “She attempted suicide at 6 years old. Is 6 years old ! », says the DD Some charm. Then she made a second suicide attempt at age 11, while still taking the medication.
When the doctor first met the girl at the age of 12, she was quick to get her to stop the treatment.
Singulair – its generic name montelukast – is a medication approved for the treatment of asthma in adults and children and to help control the nasal symptoms of seasonal allergies.
When it was marketed in 1997 in Canada, the manufacturer at the time, Merck, noted few side effects in clinical trials. “There was a little bit of nausea, a little bit of stomach ache, a little bit of headache, but nothing major. There were no neuropsychiatric side effects,” recalls the DD Francine Ducharme.
It was not until 2008 that new reports prompted Health Canada and the FDA to update the drug’s list of side effects to include depression, suicidal thoughts and behaviors and anxiety.
Side effects may appear differently in adults. “The effects we see are often nightmares. I’ve had a few cases where people had anxiety issues. People also said that they were in a worse mood,” says the DD Krystelle Godbout, pulmonologist at the University Institute of Cardiology and Pneumology of Quebec (IUCPQ), specializing in asthma in adults. She sees patients with medication side effects a few times a year.
An “inaccurate” warning
To date, Health Canada has received more than 4,000 reports of adverse reactions related to Singulair. Of these, “3,116 reports were serious,” says agency spokesperson Mark Johnson.
PHOTO ROBERT SKINNER, THE PRESS
The DD Francine Ducharme, pediatrician and clinical epidemiologist at CHU Sainte-Justine
Health professionals were also warned by Health Canada of the risk of serious neuropsychiatric events associated with montelukast, by means of a new mention of “serious warnings and precautions” in August 2020. This mention constitutes the type strongest warning for a product in Canada.
“The benefits of Singulair in some patients may not outweigh the risks, especially when the symptoms of the disease are mild and can be well controlled with other treatments,” reads the warning. Health Canada.
The DD Ducharme believes, however, that Health Canada’s warning does not reveal the extent of the problem. In the product monograph dating from 2021, we can read that adverse effects have been reported very rarely, i.e. in less than 1 case in 10,000. “It is inaccurate to say that it happens less than 1 in 10,000,” exclaims the DD Some charm. “This suggests that patients, pharmacists and doctors should more systematically report any side effects. »
Instead, Health Canada is of the opinion that “the warnings included in the current product monograph are up to date and communicate the risks in question.”
“Reporting adverse effects is taken seriously,” said Dominique Quirion of Organon, manufacturer of Singulair since 2021. “As with all our medicines, we continually monitor the safety of Singulair. »
A few months before Health Canada, the Food and Drug Administration (FDA) in the United States had also requested that a framed warning, or Black box warning in English, be added to the prescribing information for montelukast to describe its serious mental health side effects.
The FDA also announced that it had identified 82 cases of suicide associated with the drug, including 19 in children. “Please be aware that some patients have reported neuropsychiatric events after stopping montelukast,” the agency specifies on its website.
When the DD Krystelle Godbout completed her pulmonology course in 2014, the side effects of the drug Singulair were little known. “I was prescribing Singulair to patients and I didn’t tell them about the side effects, because it wasn’t well publicized. »
There has been much greater awareness of neuropsychiatric effects since the FDA issued its Black box warning in 2020. However, she believes that Health Canada’s warning remains, to this day, unnoticed compared to that of our neighbors to the South. “Health Canada’s warnings, I would say, are less well publicized. THE Black box, it’s scary. »
At least 38,000 users in Quebec
Despite serious warnings from the federal agency, the drug is still prescribed. In 2023, more than 38,000 people will use the drug Singulair, a constant increase over the last 10 years, according to data from the Régie de l’assurance santé du Québec (RAMQ) obtained by The Press. This data only concerns people insured by the public system.
“It is never a first choice in asthma,” says the DD Krystelle Godbout. We will use Singulair in adults in addition to pumps [de corticostéroïdes] when they are not sufficient to control asthma. »
Singulair has the advantage of being a tablet medication, says the specialist. “Patients forget the pumps a lot, whereas they take medication by mouth quite regularly. » Singulair can also help avoid increasing doses of cortisones in pumps which can have long-term adverse effects.
To have access to advanced therapies against asthma, i.e. injection medications reimbursed by the RAMQ, the government also requires “that there has been a trial of Singulair or another medication before being able to access to these advanced therapies,” she says.
“I felt like my son had taken drugs”
Although consumption of the drug by minors has decreased in the last 10 years, more than 2,000 children under the age of 10 are still treated with this drug.
Singulair is often prescribed when other asthma treatments prove ineffective, explains Dr.r Larry Lands, director of the division of respiratory medicine at the Montreal Children’s Hospital.
This is the case of Mylène*’s son, who was barely 1 year old when he started taking Singulair last year. The toddler had tried two other medications previously, without success.
The beneficial effects of Singulair were instantaneous. “It was magical. The asthma is completely gone. This had never happened before her asthma was controlled,” says Mylène.
The family had been warned by the medical team to carefully monitor the possible neurological effects of the medication. “But the pharmacist told me that it was an old molecule and that the medicine had existed for a long time and that we didn’t have to worry. »
In the days that followed, she noticed that her son had become hyperactive. “We weren’t even able to read him a book, we always had to be in the movement. » She discussed it during her son’s follow-up in the hospital. The family and the medical team concluded that the benefits were greater than the risks.
However, the weeks passed and his agitation only increased. “There was one evening when I could no longer get in touch with him. Everything stimulated him: the heat, the colors. I felt like my son had taken drugs. »
The family stopped the medication the next day. A week later, the boy was back to his normal self. “He came and hugged us and stayed glued to us. He never did that. We realized that the medicine had really had a big effect on him. »
*The first name has been changed so as not to reveal the identity of the child.