Montelukast with Rifampin Interaction Details
Brand Names Associated with Montelukast
- Montelukast
- Singulair®
Brand Names Associated with Rifampin
- Rifadin®
- Rifamate® (as a combination product containing Isoniazid, Rifampin)
- Rifampin
- Rifater® (as a combination product containing Isoniazid, Pyrazinamide, Rifampin)
- Rimactane®

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 10, 2023
Interaction Effect
Decreased bioavailability of montelukast
Interaction Summary
Rifampin is a potent inducer of the cytochrome P450 system. When phenobarbital, also a potent inducer, was given with a single dose of montelukast 10 mg, the area under the concentration-time curve (AUC) of montelukast decreased approximately 40%. Although no studies have been conducted with rifampin and montelukast, the patient should be monitored for clinical efficacy of montelukast.
Severity
Minor
Onset
Rapid
Evidence
Probable
How To Manage Interaction
The patient should be monitored for continued clinical effectiveness of montelukast when rifampin is administered concurrently.
Mechanism Of Interaction
Induction of montelukast metabolism by rifampin
Montelukast Overview
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Montelukast is used to prevent wheezing, difficulty breathing, chest tightness, and coughing caused by asthma in adults and children 12 months of age and older. Montelukast is also used to prevent bronchospasm (breathing difficulties) during exercise in adults and children 6 years of age and older. Montelukast is also used to treat the symptoms of seasonal (occurs only at certain times of the year), allergic rhinitis (a condition associated with sneezing and stuffy, runny or itchy nose) in adults and children 2 years of age and older, and perennial (occurs all year round) allergic rhinitis in adults and children 6 months of age and older. Montelukast should be used to treat seasonal or perennial allergic rhinitis only in adults and children who cannot be treated with other medications. Montelukast is in a class of medications called leukotriene receptor antagonists (LTRAs). It works by blocking the action of substances in the body that cause the symptoms of asthma and allergic rhinitis.
Rifampin Overview
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Rifampin is used with other medications to treat tuberculosis (TB; a serious infection that affects the lungs and sometimes other parts of the body). Rifampin is also used to treat some people who have Neisseria meningitidis (a type of bacteria that can cause a serious infection called meningitis) infections in their noses or throats. These people have not developed symptoms of the disease, and this treatment is used to prevent them from infecting other people. Rifampin should not be used to treat people who have developed symptoms of meningitis. Rifampin is in a class of medications called antimycobacterials. It works by killing the bacteria that cause infection.
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Antibiotics such as rifampin will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.