Note: This document contains side effect information about montelukast. Some of the dosage forms listed on this page may not apply to the brand name Singulair.
Applies to montelukast: oral packet, oral tablet, oral tablet chewable
Along with its needed effects, montelukast (the active ingredient contained in Singulair) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking montelukast:
Incidence not known
Some side effects of montelukast may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Incidence not known
Applies to montelukast: oral granule, oral tablet, oral tablet chewable
The most common adverse reactions (incidence more than 5% and greater than placebo) were: Upper respiratory infection, fever, headache, pharyngitis, cough, abdominal pain, diarrhea, otitis media, influenza, rhinorrhea, sinusitis, otitis.
Very rare (less than 0.01%): Churg-Strauss Syndrome
Churg-Strauss syndrome is a rare granulomatous eosinophilic condition that involves the upper and lower airways and manifests as rhinitis, sinusitis and asthma. If untreated the syndrome may progress to systemic vasculitis, peripheral neuropathy and potentially fatal cardiac complications. In most cases, the condition emerged during withdrawal of oral corticosteroid therapy. A causative role for leukotriene receptor antagonists has not been ruled out.
Very common (10% or more): Headache (18.4%)
Common (1% to 10%): Dizziness (1.9%)
Postmarketing reports: Disturbance in attention, irritability, memory impairment, tremor, drowsiness, paraesthesia/hypoesthesia, seizures
Common (1% to 10%): Rash (1.6%), atopic dermatitis, skin infection, eczema, urticaria
Postmarketing reports: Angioedema, bruising, erythema multiforme, erythema nodosum, pruritus, Stevens-Johnson syndrome/toxic epidermal necrolysis
Common (1% to 10%): Abdominal pain (2.9%), dyspepsia (2.1%), dental pain (1.7%), gastroenteritis (1.5%), nausea, diarrhea, dyspepsia, gastroenteritis, tooth infection
Common (1% to 10%): ALT increase (2.1%), AST increased (1.6%)
Postmarketing reports: Hepatic eosinophilic infiltration; cases of cholestatic hepatitis, hepatocellular liver-injury, and mixed-pattern liver injury. Most of these occurred in combination with other confounding factors, such as use of other medications, or when administered to patients who had underlying potential for liver disease such as alcohol use or other forms of hepatitis.
Common (1% to 10%): Myopia, conjunctivitis
Common (1% to 10%): Asthenia, fatigue (1.8%), fever (1.5%), trauma (1%), influenza, fever, otitis, viral infection, varicella, ear pain, otitis media
Uncommon (0.1% to 1%): Malaise
Postmarketing reports: Edema
Common (1% to 10%): Influenza (4.2%), cough (2.7%), nasal congestion (1.6%), pharyngitis, sinusitis, laryngitis, infective rhinitis, acute bronchitis, rhinorrhea, pneumonia, upper respiratory infection, wheezing, tonsillitis
Postmarketing reports: Epistaxis, pulmonary eosinophilia
Postmarketing reports: Palpitations
Postmarketing reports: Enuresis in children
Postmarketing reports: Increased bleeding tendency, thrombocytopenia
Postmarketing reports: Anaphylaxis
Postmarketing reports: Arthralgia, myalgia including muscle cramps
Postmarketing reports: Agitation including aggressive behavior or hostility, anxiousness, depression, disorientation, dream abnormalities, hallucinations, insomnia, restlessness, somnambulism, suicidal thinking and behavior (including suicide)
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Singulair