Clarithromycin with Bosentan Interaction Details
Brand Names Associated with Clarithromycin
- Biaxin® Filmtab®
- Biaxin® Granules
- Biaxin® XL Filmtab
- Biaxin® XL Pac
- Clarithromycin
Brand Names Associated with Bosentan
- Bosentan
- Tracleer®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 08, 2023
Interaction Effect
Increased bosentan plasma concentrations
Interaction Summary
Bosentan is primarily metabolized in the liver by CYP2C9 and CYP3A4 enzymes. Although the interaction between bosentan and clarithromycin has not been studied, concomitant use of bosentan 125 mg twice daily and ketoconazole, another potent CYP3A4 inhibitor, resulted in a 2-fold increase in bosentan plasma concentrations in healthy volunteers. While no dose adjustment is necessary when bosentan and clarithromycin are used together, patients may need to be monitored for increased bosentan adverse effects (headache, hypotension, flushing, decreased hemoglobin). Additionally, CYP2C9 inhibitors, such as fluconazole and amiodarone, may also increase bosentan levels. Therefore, coadministration of combinations of CYP2C9 inhibitors and a CYP3A4 inhibitor, including clarithromycin, with bosentan is not recommended.
Severity
Moderate
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
Monitor patients for increased bosentan adverse effects (headache, hypotension, flushing, decreased hemoglobin) when bosentan and clarithromycin are coadministered as increased bosentan plasma concentrations may occur. Concomitant use of bosentan and ketoconazole, another potent CYP3A4 inhibitor, resulted in a 2-fold increase in bosentan plasma concentrations. A dose adjustment is not necessary when clarithromycin and bosentan are coadministered. In addition, bosentan is also metabolized by CYP2C9 enzymes. Therefore, coadministration of clarithromycin and a CYP2C9 inhibitor, such as amiodarone or fluconazole, with bosentan is not recommended.
Mechanism Of Interaction
Inhibition of CYP3A4-mediated bosentan metabolism by clarithromycin
Clarithromycin Overview
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Clarithromycin is used to treat certain bacterial infections, such as pneumonia (a lung infection), bronchitis (infection of the tubes leading to the lungs), and infections of the ears, sinuses, skin, and throat. It also is used to treat and prevent disseminated Mycobacterium avium complex (MAC) infection [a type of lung infection that often affects people with human immunodeficiency virus (HIV)]. It is used in combination with other medications to eliminate H. pylori, a bacterium that causes ulcers. Clarithromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria.
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Antibiotics such as clarithromycin will not work for colds, flu, or other viral infections. Taking antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.
Bosentan Overview
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Bosentan is used to treat pulmonary arterial hypertension (PAH, high blood pressure in the vessels that carry blood to the lungs) in adults and children 3 years of age and older. Bosentan may improve the ability to exercise and slow the worsening of symptoms in patients with PAH. Bosentan is in a class of medications called endothelin receptor antagonists. It works by stopping the action of endothelin, a natural substance that causes blood vessels to narrow and prevents normal blood flow in people who have PAH.
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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.