Alfuzosin and Cobicistat: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cobicistat
Alfuzosin
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased alfuzosin exposure
Interaction Deep Dive
Although the interaction between alfuzosin, a CYP3A4 substrate1, and cobicistat, a CYP3A4 inhibitor 4, has not been studied, the interaction between alfuzosin and ketoconazole, a potent CYP3A4 inhibitor, resulted in 2 to 3-fold increases in alfuzosin Cmax and AUC values. The interaction between alfuzosin and diltiazem, a moderately potent CYP3A4 inhibitor, resulted in 1.5-fold and 1.3-fold increase in alfuzosin Cmax and AUC values respectively 1. Because of the potential for serious reactions, such as hypotension, the concomitant use of these two agents is contraindicated 456.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of alfuzosin by cobicistat
Literature reports
2 reports — tap to read
a) Although the potential for an interaction between alfuzosin and cobicistat has not been investigated, pharmacokinetic studies have demonstrated that coadministration of alfuzosin with ketoconazole, a potent CYP3A4, inhibitor increases alfuzosin exposure. In one study, alfuzosin Cmax and AUC were increased by 2.3-fold and 3.2-fold, respectively, when patients received repeated ketoconazole doses of 400 mg/day followed by a single 10 mg alfuzosin dose. In another study, alfuzosin Cmax and AUC were increased by 2.1- and 2.5-fold when patients received repeated ketoconazole doses of 200 mg/day followed by a single 10 mg alfuzosin dose 3.
b) Although the potential for an interaction between alfuzosin and cobicistat has not been investigated, a pharmacokinetic study demonstrated an interaction between alfuzosin and diltiazem, a moderately potent CYP3A4 inhibitor. Coadministration of repeated doses of diltiazem 240 mg/day and alfuzosin 7.5 mg/day increased the Cmax and AUC of alfuzosin 1.5-fold and 1.3-fold, respectively. Alfuzosin increased the Cmax and AUC of diltiazem 1.4-fold 2.
Common questions
Can I take Alfuzosin and Cobicistat together?
Increased alfuzosin exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Alfuzosin and Cobicistat interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Alfuzosin or Cobicistat need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (6)
- Product Information: UROXATRAL(R) extended-release oral tablets, alfuzosin HCL extended-release oral tablets. Sanofi-aventis, Bridgewater, NJ, 2010. DailyMed
- Product Information: UROXATRAL(R) oral extended-release tablets, alfuzosin HCl oral extended-release tablets. Sanofi-Aventis US LLC, Bridgewater, NJ, 2008. DailyMed
- Product Information: UROXATRAL(R) extended release oral tablets, alfuzosin hcl extended release oral tablets. Sanofi-Aventis, Bridgewater, NJ, 2010.
- Product Information: STRIBILD(R) oral tablets, elvitegravir cobicistat emtricitabine tenofovir disoproxil fumarate oral tablets. Gilead Sciences Inc (per FDA), Foster City, CA, 2021. DailyMed
- Product Information: SYMTUZA(R) oral tablets, darunavir, cobicistat, emtricitabine, tenofovir alafenamide oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2023. DailyMed
- Product Information: EVOTAZ(R) oral tablets, atazanavir cobicistat oral tablets. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2023. DailyMed
Keep reading about Cobicistat
Keep reading about Alfuzosin
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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