Psychiatric Side Effects from a Common Asthma Treatment

The latest video posted to 15-Minute Pharmacology is a lecture by Dr. Sara Dugan about the psychiatric side effects of a popular asthma and allergy medicine.

What is Montelukast?

Montelukast is the generic name for a medicine that’s also sold under the brand name, Singulair. It’s usually prescribed to treat asthma. It can also be prescribed to treat allergies.

Shortly after montelukast entered clinical practice, I started getting calls and messages — usually from parents — about the new onset of mood changes, suicidal ideas, or psychosis in people who took this medication.

In March 2020, the FDA required a boxed warning be added to the montelukast prescribing information. (Boxed warnings are the most prominent form of warning in the FDA safety communication system.)

The most likely explanation for the potential for psychiatric side effects from montelukast lies in the medicine’s unique mechanism of action. The drug prevents the conversion of an omega-6 fatty acid (arachidonic acid) into a signaling molecule known as leukotriene. Leukotrienes are inflammation molecules, so blocking their formation can be a good way to treat asthma.

But in blocking the path from arachidonic acid to leukotriene, the arachidonic acid is probably pushed into other pathways (like the prostaglandin pathway) whose products can interact with neurotransmitters that influence mood and behavior.

Learn more:

In this video, Dr. Sara Dugan reviews the psychiatric side effects of montelukast.

This lecture was given at the January 12, 2021 meeting of the SZconsult learning community.

SZconsult is a free consultation and education service offered by Northeast Ohio Medical University. It’s open to any clinician who wants to learn more about schizophrenia-spectrum illness, or who wants to tap into the collective wisdom of the learning community to find answers to clinical problems.


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