Subscribe Now
Subscribe Now

Although Singulair or montelukast remains among the most frequently prescribed medicines with more than 25 million prescriptions each year, the drug is not very effective.  It routinely fails to live up to expectations.  Typically employed to treat nasal allergies, rhinitis or hay fever it may be administered to prevent asthma or breathing disorders associated with exercise. 

Some doctors also prescribe Singulair off-label for individuals suffering from hives, itchy skin and for wheezing episodes in children.       


The dose remains one tablet daily in the evening except when used to prevent exercise related asthma.  These individuals should take the pill two hours before planned activities but the limit remains only one pill within any 24 hour period.  Montelukast is available for children over age 6 months as a packet of oral granules or as a chewable tablet.

Singulair from Well Now Doctor on YouTube


In theory Singulair prevents a chemical process leading to swelling of the airways and contraction of smooth muscle cells lining the respiratory passageways.  It also decreases production of mucus.  Singulair prevents release of a variety of substances from allergy cells – mast cells and eosinophils – that precipitate nasal symptoms.

Unfortunately benefits associated with Singulair tend to be minimal and at most slightly better than those associated with an inactive placebo.  This reconfirms that Singulair is not very effective.

Possibly OTC?

Some years ago the drug company behind Singulair requested permission from the FDA to combine the drug with Claritin (loratidine).  That petition was nixed.  To boost sales the company discussed moving it to the over-the-counter market rather than continuing its prescription status.  The FDA similarly squashed those plans.

Some Side Effects

More importantly the side effect profile of montelukast may be considerable.  While most people experience minimal problems, for some the adverse reactions far exceed any possible benefits. 

Mental Health Issues

Minor complaints include cough, abdominal pain, headache, sore throat and diarrhea.  Of more concern, Singulair may lead to adverse neuropsychiatric events.   Included among the potentially devastating consequences of the drug are agitation, hostility, aggressive behavior, hostility anxiety and irritability.  Additionally montelukast may be associated with depression, sleep disturbances, memory impairment, tics and suicidal thoughts and behavior.

Information regarding mental difficulties associated with Singulair have been known for over a decade.  During this time petitions from parents and interest groups to the FDA demanded limits on the use of Singulair especially for very young children.  Even a reviewer on the FDA panel commented on the lack of positive effects of the drug.  It seems for many the risks far outweigh the potential benefits.

Black Box Warning

Until recently the FDA followed a very timid line with respect to Singulair.  Over time they cautiously strengthened the label’s cautions regarding possible psychiatric harm.  Finally in the face of overwhelming evidence the hardened their position on March 4, 2020 and required the strongest warnings to doctors and patients alike.  This black box warning must now appear on the package insert. 

The FDA currently recommends other therapies before even considering Singulair.  This position certainly seems to make sense since Singulair regularly lacks any demonstrable benefit over an oral antihistamine such as Claritin (loratidine) or Allegra (fenofexadine). 

Current Status

In fact the American Academy of Allergy, Asthma & Immunology notes inhaled corticosteroids including Flonase provide more improvement with considerably less risk in treating nasal allergies.  Similarly the Global Initiative for Asthma cautions that Singulair should not be prescribed as a primary treatment for asthma.

This one time juggernaut in treating asthma and hay fever brought in annual revenue exceeding $5 billion.  With the availability of generic montelukast, sales of Singulair plummeted by about 90%.  Now the FDA has driven the stake further into further prescriptions with its latest warning.  With this evidence that Singulair is not very effective, hopefully doctors will finally exercise more restraint in prescribing this drug.

Leave a Reply

Your email address will not be published. Required fields are marked *