Drug interactions
Lopinavir + Tadalafil
Severity: Major
Lopinavir 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
Lopinavir/ritonavir inhibits CYP3A4 and increases tadalafil exposure. This can lead to severe hypotension, syncope, visual changes and priapism.
What this interaction means in plain words
Lopinavir 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.
Lopinavir belongs to Anti Virals; Tadalafil belongs to Genitourinary.
Why it happens
Ritonavir-boosted lopinavir inhibits CYP3A4, reducing tadalafil clearance.
What to do
For erectile dysfunction, apply the reduced tadalafil maximum doses in labeling and monitor for hypotension and priapism. For pulmonary hypertension, follow labeling on stopping and low-dose restart.
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?
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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 Lopinavir
- Alfuzosin + Lopinavir Contraindicated
- Avanafil + Lopinavir Contraindicated
- Cisapride + Lopinavir Contraindicated
- Dronedarone + Lopinavir Contraindicated
- Eletriptan + Lopinavir Contraindicated
- Eplerenone + Lopinavir Contraindicated
Frequently asked questions
Can I take Lopinavir with Tadalafil?
MediHelp rates the interaction as major. Lopinavir 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. Lopinavir/ritonavir inhibits CYP3A4 and increases tadalafil exposure. This can lead to severe hypotension, syncope, visual changes and priapism.
How serious is the interaction between Lopinavir 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 erectile dysfunction, apply the reduced tadalafil maximum doses in labeling and monitor for hypotension and priapism. For pulmonary hypertension, follow labeling on stopping and low-dose restart.
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.
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