Sildenafil with Rifapentine Interaction Details
Brand Names Associated with Sildenafil
- Revatio®
- Sildenafil
- Viagra®
Brand Names Associated with Rifapentine
- Priftin®
- Rifapentine
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 12, 2023
Interaction Effect
Reduced sildenafil exposure
Interaction Summary
Concomitant administration of sildenafil (a CYP3A4 substrate) with a strong CYP3A4 inducer may cause a substantial decrease in sildenafil exposure. Dose up-titration of sildenafil may be needed when initiating treatment with a strong CYP3A4 inducer. Reduce the dose of sildenafil to 20 mg three times a day when discontinuing treatment with a strong CYP3A4 inducer.
Severity
Major
Onset
Unspecified
Evidence
Probable
How To Manage Interaction
Concomitant administration of sildenafil (a CYP3A4 substrate) with a strong CYP3A4 inducer may cause a substantial decrease in sildenafil exposure. Dose up-titration of sildenafil may be needed when initiating treatment with a strong CYP3A4 inducer. Reduce the dose of sildenafil to 20 mg three times a day when discontinuing treatment with a strong CYP3A4 inducer.
Mechanism Of Interaction
Induction of CYP3A4-mediated metabolism of sildenafil
Literature Reports
A) Concomitant administration of strong CYP3A inducers is expected to cause substantial decreases in plasma levels of sildenafil .
Sildenafil Overview
-
Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Revatio) is used to improve the ability to exercise in adults and children 1 year of age and older with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness). Sildenafil is in a class of medications called phosphodiesterase (PDE) inhibitors. Sildenafil treats erectile dysfunction by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection. Sildenafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow easily.
-
If you are taking sildenafil to treat erectile dysfunction, you should know that it does not cure erectile dysfunction or increase sexual desire. Sildenafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus (HIV).
Rifapentine Overview
-
Rifapentine is used with other medications to treat active tuberculosis (TB; a serious infection that affects the lungs and sometimes other parts of the body) in adults and children 12 years of age and older. Rifapentine is also used with isoniazid (Laniazid) to treat adults and children 2 years of age and older with latent (resting or nongrowing) TB, including those in close contact with people who have active TB, a positive tuberculin skin test, human immunodeficiency virus (HIV), or those with pulmonary fibrosis (scarring of the lungs with an unknown cause). Rifapentine is in a class of medications called antimycobacterials. It works by killing the bacteria that cause infection.
-
Antibiotics such as rifapentine 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.
Return To Our Drug Interaction Homepage
Feedback, Question Or Comment About This Information?
Ask Dr. Brian Staiger, PharmD, our medical editor, directly! He's always more than happy to assist.
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.