Isosorbide Mononitrate and Sildenafil: Drug Interaction Guide

Quick answer: This is a major interaction — avoid combining Isosorbide Mononitrate and Sildenafil unless specifically directed by your doctor.

Interaction severity: Major — avoid combination

How Isosorbide Mononitrate interacts with Sildenafil

PDE-5 inhibition by sildenafil potentiates nitric oxide-mediated cGMP accumulation from nitrates, producing profound and prolonged vasodilation and hypotension.

What you should do

Contraindicated in combination; nitrates must not be administered within 24 hours of sildenafil (48 hours for tadalafil).

Key facts

Severity

Major — avoid combination

Mechanism

PDE-5 inhibition by sildenafil potentiates nitric oxide-mediated cGMP accumulation from nitrates, producing profound and...

Action

Contraindicated in combination; nitrates must not be administered within 24 hours of sildenafil (48 hours for tadalafil)...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Isosorbide Mononitrate and Sildenafil together?

No — this combination should generally be avoided. Contraindicated in combination; nitrates must not be administered within 24 hours of sildenafil (48 hours for tadalafil).

What is the severity of this interaction?

The interaction between Isosorbide Mononitrate and Sildenafil is classified as Major — avoid combination. PDE-5 inhibition by sildenafil potentiates nitric oxide-mediated cGMP accumulation from nitrates, producing profound and prolonged vasodilation and hypotension.

What should I do if I'm prescribed both?

Contraindicated in combination; nitrates must not be administered within 24 hours of sildenafil (48 hours for tadalafil). Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.