What is a contraindication for someone taking montelukast?

Montelukast is a leukotriene receptor antagonist commonly used to manage asthma and allergies. A contraindication is a specific situation or condition that makes it unsafe for a patient to take a particular medication. In this case, if a patient has a known allergy to montelukast, it presents a significant risk of an adverse reaction, which may range from mild symptoms like rashes to severe reactions such as anaphylaxis. Therefore, a documented allergy to the drug itself is a definitive contraindication, and the medication should be avoided in these patients to ensure their safety.

The other options presented do not inherently prevent someone from taking montelukast. A history of asthma attacks does not contraindicate the use of this medication; in fact, it is primarily prescribed for individuals with asthma. Age greater than 65 is not recognized as a contraindication, although caution may be warranted due to potential side effects or interactions with other medications. Coexisting lung diseases do not serve as a strict contraindication either, but they might require healthcare providers to monitor the patient more closely when using montelukast.