Montelukast (Singulair): reminder of the risk of neuropsychiatric reactions

Prescribers should be alert for neuropsychiatric reactions in patients taking montelukast and carefully consider the benefits and risks of continuing treatment if they occur.

Advice for healthcare professionals:

  • be alert for neuropsychiatric reactions in patients taking montelukast; events have been reported in adults, adolescents, and children (see list of reported events below)

  • advise patients and their caregivers to read carefully the list of neuropsychiatric reactions in the patient information leaflet and seek medical advice immediately should they occur
  • evaluate carefully the risks and benefits of continuing treatment if neuropsychiatric reactions occur
  • be aware of newly recognised neuropsychiatric reactions of speech impairment (stuttering) and obsessive–compulsive symptoms
  • report suspected adverse drug reactions associated with montelukast to the Yellow Card Scheme

Advice to give to patients and caregivers:

  • it is important you or your child do not stop montelukast without talking to a doctor or asthma nurse first
  • adverse reactions affecting sleep, behaviour, and mood have been infrequently reported in people taking montelukast
  • always read the leaflet that accompanies your or your child’s medicines, and talk to a healthcare professional if you suspect any serious reactions to montelukast
  • patients, parents, and caregivers can report suspected adverse drug reactions to medicines via the Yellow Card Scheme

Review of known risk of neuropsychiatric reactions

It has been known for some time that neuropsychiatric reactions may occur in association with montelukast treatment, and these reactions are listed as possible side effects in the product information. A recent EU review confirmed the known risks of neuropsychiatric reactions and found that the magnitude of risk was unchanged. However, the review identified some cases in which there had been a delay in neuropsychiatric reactions being recognised as a possible adverse drug reaction.

Therefore, we remind healthcare professionals of the possible risks with montelukast and the need to consider the benefits and risks of continuing treatment if they occur.

Reported neuropsychiatric reactions

A range of neuropsychiatric reactions has been reported in association with montelukast. Among these are: sleep disturbances, depression and agitation (may affect up to 1 in 100 people taking montelukast); disturbances of attention or memory (up to 1 in 1,000 people); and very rarely, hallucinations and suicidal behaviour (up to 1 in 10,000 people). See the Summary of Product Characteristics and the Patient Information Leaflet for full details.

In the UK, between 2014 and 2018, MHRA received 219 reports of suspected adverse neuropsychiatric reactions to the Yellow Card Scheme, during which time there were approximately 14 million prescriptions of montelukast. Since montelukast was first marketed in the UK, we have received 639 reports of suspected adverse neuropsychiatric reactions.

In the UK, the most frequently reported suspected neuropsychiatric reactions associated with montelukast have been nightmares/night terrors, depression, insomnia, aggression, anxiety and abnormal behaviour or changes in behaviour. These events were reported in all age groups. However, nightmare/night terrors, aggression, and behaviour changes are more frequently reported in the paediatric population.

Updated montelukast product information for patients and healthcare professionals

More information to better describe the risks of neuropsychiatric events has also been added to the Summary of Product Characteristics and Patient Information Leaflet .

The EU review also evaluated very rare reports of cases of speech impairment (dysphemia), described as ‘stuttering’. Most of the cases were reported in children younger than 5 years, occurred shortly after montelukast was started (median time to onset 8 days) and sometimes occurred in conjunction with other suspected neuropsychiatric events. Where information was provided, in most cases the events resolved on stopping treatment.

In addition, the EU review endorsed the inclusion in the product information of very rare reports of obsessive–compulsive symptoms in the product information. Cases of obsessive-compulsive symptoms were reported to generally occur after a longer treatment period (median time to onset of 61 days) and sometimes occurred in conjunction with other neuropsychiatric events. Where information was provided, in most cases the events resolved on stopping treatment.

The product information is also being updated to include stuttering and obsessive-compulsive symptoms as very rare (thought to affect fewer than 1 in 10,000 patients) potential neuropsychiatric adverse events with montelukast.

About montelukast (Singulair)

Montelukast sodium is an oral leukotriene receptor antagonist. It is indicated for patients 6 months and older:

  • for the treatment of asthma as add-on therapy in those patients with mild to moderate persistent asthma who are inadequately controlled on inhaled corticosteroids and in whom “as-needed” short acting beta-agonists provide inadequate clinical control of asthma.
  • in those asthmatic patients in whom montelukast is indicated, montelukast can also provide symptomatic relief of seasonal allergic rhinitis.
  • for the prophylaxis of asthma in which the predominant component is exercise-induced bronchoconstriction.

Report any suspected adverse reactions on a Yellow Card

Healthcare professionals and patients should continue to report any suspected adverse drug reactions associated with montelukast to the Yellow Card Scheme.

It is easy to report on the Yellow Card website or via the Yellow Card app. Download the app today via iTunes Yellow Card for iOS devices or via PlayStore Yellow Card for Android devices.

You can also use the app to access the latest safety information from the MHRA about medicines and medical devices on the Newsfeed. Search for medicines to see details of Yellow Card reports others have made. Medicines of interest can also be added to a Watch List to receive news and alerts about new side effects and safety advice as it emerges.

Further Information

European Medicines Agency. Scientific Conclusions report. July 2019.

Article citation: Drug Safety Update volume 13, issue 2: September 2019: 4.

Published 19 September 2019