Drug interactions
Nitroglycerin rectal + Tadalafil
Severity: Contraindicated
Nitroglycerin rectal and Tadalafil: contraindicated interaction.
Last updated
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
Tadalafil markedly enhances the blood pressure lowering effect of rectal nitroglycerin. Severe hypotension may occur and the risk lasts well beyond the dose because of tadalafil's long half-life.
What this interaction means in plain words
Nitroglycerin rectal and Tadalafil are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
Additive cGMP-mediated vasodilation from nitric oxide donation and PDE5 inhibition.
What to do
Avoid combination; keep nitrates at least 48 hours away from tadalafil. Use non-nitrate therapy within that window.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Nitroglycerin rectal 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 14 days on the web. No card needed.
Other interactions of Tadalafil
- Amyl nitrite + Tadalafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide mononitrate + Tadalafil Contraindicated
- Nitroglycerin po + Tadalafil Contraindicated
- Nitroglycerin sublingual + Tadalafil Contraindicated
- Nitroglycerin transdermal + Tadalafil Contraindicated
Frequently asked questions
Can I take Nitroglycerin rectal with Tadalafil?
MediHelp rates the interaction as contraindicated. Nitroglycerin rectal and Tadalafil are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Tadalafil markedly enhances the blood pressure lowering effect of rectal nitroglycerin. Severe hypotension may occur and the risk lasts well beyond the dose because of tadalafil's long half-life.
How serious is the interaction between Nitroglycerin rectal and Tadalafil?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combination; keep nitrates at least 48 hours away from tadalafil. Use non-nitrate therapy within that window.
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.
