Drug interactions
Cobicistat + Tadalafil
Severity: Major
Cobicistat and Tadalafil: major interaction.
Last updated Sources: US FDA label
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Cobicistat is a strong CYP3A4 inhibitor and markedly increases tadalafil exposure. This raises the risk of hypotension, priapism, syncope and visual effects.
What this interaction means in plain words
Cobicistat and Tadalafil can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Cobicistat belongs to Miscellaneous; Tadalafil belongs to Genitourinary.
Why it happens
Strong inhibition of CYP3A4-mediated tadalafil metabolism by cobicistat.
What to do
For PAH, avoid starting tadalafil in the first week, then begin at 20 mg daily and titrate as tolerated. For ED, limit tadalafil to a single low dose at long intervals and monitor for hypotension.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cobicistat and Tadalafil, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
Other interactions of Tadalafil
- Amyl nitrite + Tadalafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide mononitrate + Tadalafil Contraindicated
- Nitroglycerin po + Tadalafil Contraindicated
- Nitroglycerin rectal + Tadalafil Contraindicated
- Nitroglycerin sublingual + Tadalafil Contraindicated
Other interactions of Cobicistat
- Alfuzosin + Cobicistat Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Cobicistat + Colchicine Contraindicated
- Cobicistat + Dronedarone Contraindicated
- Cobicistat + Eletriptan Contraindicated
- Cobicistat + Eplerenone Contraindicated
Frequently asked questions
Can I take Cobicistat with Tadalafil?
MediHelp rates the interaction as major. Cobicistat and Tadalafil can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Cobicistat is a strong CYP3A4 inhibitor and markedly increases tadalafil exposure. This raises the risk of hypotension, priapism, syncope and visual effects.
How serious is the interaction between Cobicistat and Tadalafil?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: For PAH, avoid starting tadalafil in the first week, then begin at 20 mg daily and titrate as tolerated. For ED, limit tadalafil to a single low dose at long intervals and monitor for hypotension.
What other medicines interact with Tadalafil?
MediHelp also lists interactions of Tadalafil with, for example, Amyl nitrite, Isosorbide dinitrate, Isosorbide mononitrate. The full list is on the Tadalafil page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
