Singulair Side Effects
Generic name: montelukast
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.
Some side effects of Singulair may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
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:Less common
- Abdominal or stomach pain
- bloody nose
- flu-like symptoms
- general feeling of discomfort or illness
- joint pain
- pain or tenderness around the eyes and cheekbones
- shortness of breath or troubled breathing
- tightness of the chest
- trouble with swallowing
- unusual tiredness or weakness
- Pus in the urine
- attempts at killing oneself
- breathing problems
- confusion about identity, place, and time
- fast, irregular, pounding, or racing heartbeat or pulse
- feeling sad or empty
- hives or welts
- itching, puffiness, or swelling of the eyelids or around the eyes, face, lips, or tongue
- lack of appetite
- pains in the stomach, side, or abdomen, possibly moving to the back
- redness of the skin
- shaking or trembling of the hands or feet
- trouble with concentrating
- unable to sleep
- unpleasant breath odor
- upper right abdominal or stomach pain
- vomiting of blood
- yellow eyes or skin
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:Less common
- Acid or sour stomach
- blurred vision
- change in near or distance vision
- dental pain
- lack or loss of strength
- skin rash, encrusted, scaly and oozing
- stomach discomfort, upset, or pain
- Burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feelings
- dreams that are unusual
- increased tendency to bleed
- large, flat, blue or purplish patches on the skin
- muscle aching or cramping
- swollen joints
For Healthcare Professionals
Applies to montelukast: oral granule, oral tablet, oral tablet chewable
Nervous system side effects have included headache (18% to 20%) and dizziness (2%). Isolated and rare reports of somnolence have been associated with the use of higher than recommended doses. Seizures have been reported very rarely. Paresthesias, hypoesthesia, and drowsiness and have been reported in postmarketing experiences.
Respiratory system side effects have included influenza (4%), cough (3%), and nasal congestion (2%). In some studies, upper respiratory tract infection (28%) and worsened asthma (4% to 11%) were associated with the use of this drug. However, many patients with asthma have some or all of these symptoms, and a causal relationship has not been proven. Rhinorrhea, sinusitis, otitis, influenza, epistaxis, and pneumonia have also been reported.
Postmarketing reports have included thoracic and mediastinal disorders.
Gastrointestinal side effects have included abdominal pain, dyspepsia, or infectious gastroenteritis in up to 3% of patients. Diarrhea has been associated with the use of higher than recommended doses.
Postmarketing reports have included vomiting.
In general, montelukast (the active ingredient contained in Singulair) is well tolerated. Asthenia, fatigue, or fever has been associated with the use of this drug in approximately 2% of patients. Varicella has also been reported.
Dermatologic side effects have included rash, eczema, urticaria, and dermatitis. Postmarketing experience has included erythema multiform.
Postmarketing reports include Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).
Churg-Strauss syndrome has been reported in association with montelukast therapy.
Hepatic side effects have included elevated hepatic serum transaminases in approximately 2% of patients. Pancreatitis has been reported very rarely. Jaundice with elevated liver enzymes are described in a 42 year old man several months after starting montelukast (the active ingredient contained in Singulair) therapy. Serum enzymes completely normalized 4 months after drug withdrawal.
Postmarketing experience has reported rare cases of cholestatic hepatitis, hepatocellular liver injury and mixed pattern liver injury.
Other side effects have included isolated cases of Churg-Strauss syndrome, a rare systemic vasculitis associated with asthma.
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.
Musculoskeletal side effects have included myalgia, muscle cramps, and muscle aches. Postmarketing experience has reported arthralgia.
Hematologic side effects have included increased bleeding tendencies and bruising. Thrombocytopenia has also been reported.
Ocular side effects have included conjunctivitis.
Psychiatric side effects have included agitation including aggressive behavior and hostility, anxiousness, dream abnormalities and hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor.
Postmarketing reports include disorientation, insomnia, and somnambulism.
Hypersensitivity side effects have included anaphylaxis, erythema nodosum, pruritus, urticaria, and very rarely hepatic eosinophilic infiltration. Postmarketing reports have included angioedema.
Postmarketing reports have included palpitations and edema.
More Singulair resources
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