Australia's Therapeutic Goods Administration has mandated warning labels on an asthma drug prescribed to millions of children that has been linked to suicidal thoughts, hallucinations and other psychiatric conditions.
U.S. government-backed research has found that montelukast, sold under the brand name Singulair, attaches to cells in the brain that control mood, decision-making, attention, impulse control and sleep.
Over the past decade, the TGA in Australia has received approximately 200 reports of behavioral adverse events associated with montelukast.
This includes 57 cases of depression, 60 cases of suicidal thoughts and 17 suicide attempts or incidents of deliberate self-harm.
There were seven cases in which patients taking the drug committed suicide.
While these figures are concerning, Nial Wheate, professor of pharmaceutical chemistry at Macquarie University, stressed the need to consider them in the context of the number of Australians using the drug.
'Over the same period, more than 200,000 scripts for montelukast have been completed under the Pharmaceutical Benefits Scheme.
“Overall, we don't know for certain that montelukast causes depression and suicide, only that it appears to increase the risk for some people.”
Australian-born Harrison Sellick attempted suicide at the age of five, a few years after going on Singulair. His mother Vanessa said that from the age of two he started having “really long meltdowns”, as well as “general comments about death and self-loathing”.
Montelukast, sold under the brand name Singulair, is a commonly prescribed drug in Australia
Dr. Wheate urged anyone with concerns to consult their doctor.
'If you have asthma and are taking montelukast or your child is, you should not simply stop taking the drug as you may be at risk of having an attack that could be life-threatening.
'If you are concerned, talk to your doctor. He can discuss the risks and benefits of the medicine for you and, if necessary, prescribe another medicine.'
As a daily pill, montelukast works by blocking chemicals released by the body that cause the airways to swell and constrict during an asthma attack.
Since the 1990s, it has been commonly prescribed to asthma patients whose condition cannot be controlled with usual treatment.
Controversy has existed for years surrounding the drug and its potential to cause suicidal thoughts.
Campaigners have repeatedly called for more efforts to make patients and parents aware of the potential risk.
These calls have now been amplified after the results of a study into the drug and its impact on the brain were announced in the US.
Presented last year at the American College of Toxicology, representatives from the U.S. Food and Drug Administration's National Center for Toxicological Research confirmed a link between the drug and psychiatric conditions.
They said laboratory tests showed “significant binding” of montelukast to multiple receptor cells in the brain and that this was highest in cells known to be involved in psychiatric effects.
However, the experts have not suggested that the drug should be withdrawn from the market or banned. They add that the investigations are still ongoing and results have not yet been finalized.
Singulair was a blockbuster product for Merck after its launch in 1998, providing relief for asthma sufferers in the form of a pill as an alternative to an inhaler.
A 2017 analysis from Kiplinger, a business forecasting company, suggested the drug had generated nearly $50 billion in sales for Merck since it came to market.
In early advertising, the company said the side effects were so benign they were “similar to a sugar pill,” while the label said the effect on the brain was minimal.
By 2019, health authorities had received thousands of reports of psychiatric episodes in patients prescribed the drug, including dozens of suicide cases.
Among them was Harrison Sellick, a Melbourne boy who attempted suicide at the age of just five.
According to his mother Vanessa, Harrison was prescribed montelukast when he was two years old, but developed behavioral problems and suicidal thoughts over the next three years.
Virginia native Nicholas England fatally shot himself in the head at age 22, just weeks after taking the generic version of Singulair
Ms Sellick told Daily Mail Australia that her son, now 17 and unmedicated, tried to kill himself at just five years old: 'He would have very long meltdowns that could last an hour and a half. There were general comments about death and self-loathing.”
In another heartbreaking story, Robert England's 22-year-old son, Nick, committed suicide in 2017, less than two weeks after starting montelukast.
England recalled that his son had trouble sleeping before he died, and said he was perfectly healthy and had no mental health problems before taking the drug.
“He was only on that drug for a few days, literally just a few days,” England said. “It completely changed the trajectory of our lives.”
Organon, a Merck spin-off that now markets Singulair, said in a statement after news of the U.S. study that it is confident in the drug's safety profile.
“The product label for Singulair contains appropriate information about the benefits, risks and reported side effects of Singulair,” the company said.
