Drug interactions
Diltiazem + Sildenafil
Severity: Moderate
Diltiazem and Sildenafil: moderate 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
Diltiazem is a moderate CYP3A4 inhibitor and may increase sildenafil exposure. It also lowers blood pressure, so hypotension and other sildenafil adverse effects such as headache and flushing may be more pronounced.
What this interaction means in plain words
Diltiazem and Sildenafil can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Diltiazem belongs to Cardiovascular; Sildenafil belongs to Genitourinary.
Why it happens
Diltiazem inhibits CYP3A4, reducing sildenafil clearance, plus additive vasodilation.
What to do
Consider starting sildenafil at 25 mg in patients taking diltiazem and monitor blood pressure and tolerability.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Atazanavir + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
Other interactions of Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Frequently asked questions
Can I take Diltiazem with Sildenafil?
MediHelp rates the interaction as moderate. Diltiazem and Sildenafil can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Diltiazem is a moderate CYP3A4 inhibitor and may increase sildenafil exposure. It also lowers blood pressure, so hypotension and other sildenafil adverse effects such as headache and flushing may be more pronounced.
How serious is the interaction between Diltiazem and Sildenafil?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider starting sildenafil at 25 mg in patients taking diltiazem and monitor blood pressure and tolerability.
What other medicines interact with Sildenafil?
MediHelp also lists interactions of Sildenafil with, for example, Amyl nitrite, Atazanavir, Cobicistat. The full list is on the Sildenafil page.
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