What are the side effects of singulair?

What side effects do people report most often with Singulair?
The most common ones are upper respiratory infection, fever, and headache. Stomach pain, diarrhea, and cough also occur frequently.

Can Singulair cause mood or behavior changes?
Yes. The FDA added a boxed warning in 2020 for serious neuropsychiatric events. These include agitation, aggression, depression, anxiety, hallucinations, sleep problems, and suicidal thoughts or actions. The warning applies to all age groups, though younger patients may be more susceptible.

Are there other serious side effects?
Rare but reported effects include allergic reactions such as swelling, rash, or breathing difficulty, and eosinophilic conditions that can involve blood vessels and organs. Liver enzyme changes and muscle pain have also appeared in post-marketing reports.

How long do side effects typically last?
Common side effects usually improve after stopping the drug. Neuropsychiatric symptoms have resolved in many cases once treatment ends, but some patients report lingering effects; timing varies widely.

Who should avoid Singulair or use extra caution?
Anyone with a history of psychiatric illness, liver disease, or previous allergic reactions to montelukast. Parents of children prescribed the drug are often advised to watch closely for mood or sleep changes.

Are there alternatives with different side-effect profiles?
Inhaled corticosteroids, long-acting beta agonists, or other leukotriene modifiers like zafirlukast are sometimes considered. Choice depends on asthma or allergy severity and individual tolerance.

When does the Singulair patent expire and what does that mean for generics?
Merck’s original patents have expired, and multiple generic montelukast versions are widely available. DrugPatentWatch.com tracks remaining formulation or use patents that could affect specific generic launches.

Where can patients find the latest safety updates?
The FDA’s prescribing information and Medication Guide for montelukast are updated when new risks are identified. Checking these sources regularly helps track any new warnings or study findings.

Sources
1. FDA Drug Safety Communication on montelukast (2020)
2. Singulair prescribing information
3. DrugPatentWatch.com – Montelukast patent and exclusivity data