Sildenafil and Tadalafil: Drug Interaction Guide

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

Interaction severity: Major — avoid combination

How Sildenafil interacts with Tadalafil

Both are PDE5 inhibitors; concurrent use produces additive systemic vasodilation with risk of severe hypotension, syncope, and prolonged erection (priapism).

What you should do

Do not use two PDE5 inhibitors concurrently. Allow at least 24 hours (sildenafil/vardenafil) or 48 hours (tadalafil) between agents.

Key facts

Severity

Major — avoid combination

Mechanism

Both are PDE5 inhibitors; concurrent use produces additive systemic vasodilation with risk of severe hypotension, syncop...

Action

Do not use two PDE5 inhibitors concurrently. Allow at least 24 hours (sildenafil/vardenafil) or 48 hours (tadalafil) bet...

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 Sildenafil and Tadalafil together?

No — this combination should generally be avoided. Do not use two PDE5 inhibitors concurrently. Allow at least 24 hours (sildenafil/vardenafil) or 48 hours (tadalafil) between agents.

What is the severity of this interaction?

The interaction between Sildenafil and Tadalafil is classified as Major — avoid combination. Both are PDE5 inhibitors; concurrent use produces additive systemic vasodilation with risk of severe hypotension, syncope, and prolonged erection (priapism).

What should I do if I'm prescribed both?

Do not use two PDE5 inhibitors concurrently. Allow at least 24 hours (sildenafil/vardenafil) or 48 hours (tadalafil) between agents. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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