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Prevents breathing problems. Singulair (Montelukast) has fewer side effects but doesn't work as well as steroid inhalers for asthma. It also helps with allergies.Coming soon.
How it works
Singulair (Montelukast) is a leukotriene inhibitor. It lowers inflammation in your lungs and nasal passages to prevent asthma and relieve allergies.Coming soon.
Type of medication
Leukotriene modifier
Prescription only
Coming soon.
Available as
  • Pill
  • Chewable tablet
  • Granule
  • Pill
  • Extended release
  • Liquid
Used for (click to learn more)
  • Asthma Chronic obstructive pulmonary disease Exercise-induced asthma; Prophylaxis Nocturnal asthma
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Reviews & ratings
Button Group. All currently active
Button Group. All currently active
of people
say Singulair is worth it
say it works well
say it’s a big hassle
of people
say theophylline is worth it
say it works well
say it’s a big hassle
Side effects
  • Dizziness 1%
  • Muscle weakness/fatiguea/fatigue 1%
  • Decreased liver function 1%
  • Congestion, nasal 1%
  • Pain, dental 1%
More Singulair side effects »

We haven’t found good data for theophylline side effects.

FDA side effect reports for theophylline »
Risk factors for serious side effects
  • Coming soon.
Pregnancy category
  • There are reports of liver injury in people taking Singulair (Montelukast) mostly in combination with other factors such as drugs, alcohol, and liver disease. If you have any of these risk factors, your doctor will need to check your liver function periodically.
No specific alcohol-related info.
  • Granules can be taken by mouth or dissolved in liquid or soft food.
No specific food-related info.
Kidneys and liver
No specific kidneys and liver-related info.No specific kidneys and liver-related info.
No specific sex-related info.No specific sex-related info.
  • Can cause behavior changes, agitation, aggression, and difficulty sleeping for some people.
  • Rare cases of behavior changes occur in adults and children taking Singulair (Montelukast). Symptoms range from irritability and memory problems to hallucinations and suicidal thinking. It is not clear if this is linked to history of these conditions. Get medical help immediately if you notice symptoms of agitation, aggression, sleep disturbance, or suicidal thoughts while taking Singulair (Montelukast).
No specific sleep-related info.
No specific weight-related info.No specific weight-related info.
Upsides and benefits
  • Prevents symptoms and improves lung function in children and adults with chronic asthma.
  • A single 10 mg dose improves exercise-induced asthma symptoms for up to 24 hours.
  • Fewer side effects compared to other asthma treatments.
  • Also relieves nasal allergy symptoms.
  • Effective pill alternative to corticosteroid inhalers.
Coming soon.
Downsides and risks
  • You have to use Montelukast every day to control your symptoms.
  • Somewhat less effective than corticosteroid inhalers for asthma.
  • There's no generic available, so it can be expensive.
  • Can cause behavior changes, agitation, aggression, and difficulty sleeping for some people.
Coming soon.
Tips from our pharmacists for people taking the medication
  • Take it once a day to control asthma and allergy symptoms.
  • If you're using it for asthma or allergies, take it in the evening.
  • Use it 2 hours before exercising.
  • Granules can be taken by mouth or dissolved in liquid or soft food.
  • Doesn't treat sudden wheezing or asthma attacks once they start. Keep a fast-acting (rescue) inhaler with you.
  • The chewable tablets contain aspartame, so don't use them if you have a sensitivity to phenylalanine or phenylketones.
Coming soon.
Learn more
More about SingulairSide effectsReviews & ratingsAlternativesFDA package insert
More about theophyllineSide effectsReviews & ratingsFDA package insert
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