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Singulair (montelukast) Disease Interactions

There are 4 disease interactions with Singulair (montelukast):


Montelukast (applies to Singulair) neuropsychiatric disorders

Major Potential Hazard, Moderate plausibility. Applicable conditions: Psychosis, Neurotic Depression, Depression

The use of montelukast is associated with neuropsychiatric events. Patients and prescribers should be alert for neuropsychiatric events. Care should be taken before using this agent in patients with any history of mental illness. If neuropsychiatric events occur during treatment, it is recommended to carefully evaluate the risks and benefits of continuing treatment with montelukast.


Montelukast (applies to Singulair) liver disorder

Moderate Potential Hazard, Moderate plausibility. Applicable conditions: Liver Disease

Reports of cholestatic hepatitis, hepatocellular liver-injury, and mixed-pattern liver injury have been reported in patients treated with montelukast sodium that had underlying potential for liver disease, such as alcohol use or other forms of hepatitis. Patients with mild-to-moderate hepatic insufficiency and clinical evidence of cirrhosis had evidence of decreased metabolism of montelukast. No dosage adjustment is required in patients with mild-to-moderate hepatic insufficiency. The pharmacokinetics of montelukast sodium in patients with more severe hepatic impairment or with hepatitis have not been evaluated. Use caution when prescribing montelukast to these patients.


Montelukast (applies to Singulair) PKU

Moderate Potential Hazard, Moderate plausibility. Applicable conditions: Phenylketonuria

Singulair (brand of montelukast) chewable tablets contain 0.842 mg of phenylalanine per each 5 mg tablet. The phenylalanine content should be considered when this product is used in patients who must restrict their intake of phenylalanine (i.e. phenylketonurics).


  1. "Product Information. Singulair (montelukast)." Merck & Co, Inc, West Point, PA.

Montelukast (applies to Singulair) pulmonary disorders

Moderate Potential Hazard, Moderate plausibility. Applicable conditions: Pulmonary Impairment

Patients with asthma on therapy with montelukast may present with systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, a condition which is often treated with systemic corticosteroid therapy. Prescribers should be alert to eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy presenting in their patients. Care should be taken before using this agent in patients with history of pulmonary disorders.

Singulair (montelukast) drug interactions

There are 86 drug interactions with Singulair (montelukast)

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.