Ketoconazole with Tadalafil Interaction Details
Brand Names Associated with Ketoconazole
- Ketoconazole
- Nizoral®
Brand Names Associated with Tadalafil
- Adcirca®
- Cialis®
- Entadfi® (as a combination product containing Finasteride, Tadalafil)
- Tadalafil
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 02, 2023
Interaction Effect
Increased tadalafil exposure
Interaction Summary
Coadministration of tadalafil and a strong CYP3A inhibitor may increase tadalafil exposure. Concomitant use of ketoconazole (a strong CYP3A4 inhibitor) and tadalafil significantly increased tadalafil AUC and Cmax in a pharmacokinetic study. Avoid concomitant use of a strong CYP3A4 inhibitor with tadalafil when used for pulmonary arterial hypertension (40 mg/day) ; additionally, coadministration with finasteride/tadalafil is not recommended . When combining a strong CYP3A inhibitor with tadalafil for erectile dysfunction and/or benign prostatic hyperplasia, do not exceed tadalafil 10 mg once every 72 hours for as needed dosing or 2.5 mg/day for daily dosing .
Severity
Major
Onset
Unspecified
Evidence
Probable
How To Manage Interaction
Coadministration of tadalafil and a strong CYP3A inhibitor may increase tadalafil exposure. Avoid concomitant use of a strong CYP3A4 inhibitor with tadalafil when used for pulmonary arterial hypertension (40 mg/day); additionally, coadministration with finasteride/tadalafil is not recommended . When combining a strong CYP3A inhibitor with tadalafil for erectile dysfunction and/or benign prostatic hyperplasia, do not exceed tadalafil 10 mg once every 72 hours for as needed dosing or 2.5 mg/day for daily dosing .
Mechanism Of Interaction
Inhibition of CYP3A-mediated metabolism of tadalafil
Literature Reports
A) Compared with the pharmacokinetics of tadalafil alone, the administration of ketoconazole (a strong CYP3A inhibitor) 400 mg daily with a single 20-mg tadalafil dose increased the AUC and Cmax of tadalafil by 312% and 22%, respectively, and coadministration of ketoconazole 200 mg daily increased tadalafil 10-mg single dose AUC and Cmax by 107% and 15%, respectively .
Ketoconazole Overview
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Ketoconazole is used to treat fungal infections when other medications are not available or cannot be tolerated. Ketoconazole should not be used to treat fungal meningitis (infection of the membranes surrounding the brain and spinal cord caused by a fungus) or fungal nail infections. Ketoconazole is in a class of antifungals called imidazoles. It works by slowing the growth of fungi that cause infection.
Tadalafil Overview
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Tadalafil (Cialis) is used to treat erectile dysfunction (ED, impotence; inability to get or keep an erection), and the symptoms of benign prostatic hyperplasia (BPH; an enlarged prostate) which include difficulty urinating (hesitation, dribbling, weak stream, and incomplete bladder emptying), painful urination, and urinary frequency and urgency in adult men. Tadalafil (Adcirca) is used to improve the ability to exercise in people with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness). Tadalafil is in a class of medications called phosphodiesterase (PDE) inhibitors. It works to treat erectile dysfunction by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection. Tadalafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow more easily.
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If you are taking tadalafil to treat erectile dysfunction, you should know that it does not cure erectile dysfunction or increase sexual desire. Tadalafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus (HIV).
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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.