Drug interactions
Diltiazem + Tamsulosin
Severity: Moderate
Diltiazem and Tamsulosin: 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 raises tamsulosin exposure, and both drugs lower blood pressure. The result can be orthostatic hypotension and dizziness.
What this interaction means in plain words
Diltiazem and Tamsulosin 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; Tamsulosin belongs to Genitourinary.
Why it happens
Inhibition of CYP3A4 metabolism of tamsulosin plus additive vasodilation.
What to do
Monitor blood pressure and orthostatic symptoms, particularly at initiation. Reduce the tamsulosin dose if hypotension occurs.
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 Tamsulosin
- Alfuzosin + Tamsulosin Major
- Avanafil + Tamsulosin Major
- Ceritinib + Tamsulosin Major
- Clarithromycin + Tamsulosin Major
- Cobicistat + Tamsulosin Major
- Doxazosin + Tamsulosin Major
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 Tamsulosin?
MediHelp rates the interaction as moderate. Diltiazem and Tamsulosin 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 raises tamsulosin exposure, and both drugs lower blood pressure. The result can be orthostatic hypotension and dizziness.
How serious is the interaction between Diltiazem and Tamsulosin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure and orthostatic symptoms, particularly at initiation. Reduce the tamsulosin dose if hypotension occurs.
What other medicines interact with Tamsulosin?
MediHelp also lists interactions of Tamsulosin with, for example, Alfuzosin, Avanafil, Ceritinib. The full list is on the Tamsulosin page.
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