Drug interactions
Diltiazem + Terazosin
Severity: Moderate
Diltiazem and Terazosin: 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
Terazosin and diltiazem both lower blood pressure, so combined use can cause additive hypotension with dizziness or syncope. Diltiazem may also modestly raise exposure to some alpha-blockers through CYP3A4 inhibition.
What this interaction means in plain words
Diltiazem and Terazosin 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; Terazosin belongs to Genitourinary.
Why it happens
Additive vasodilation from alpha-1 blockade and calcium channel blockade.
What to do
Monitor blood pressure and orthostatic symptoms when starting or changing doses. Reduce the dose of either drug if symptomatic 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 Terazosin
- Alfuzosin + Terazosin Major
- Amifostine + Terazosin Major
- Avanafil + Terazosin Major
- Doxazosin + Terazosin Major
- Dutasteride-tamsulosin + Terazosin Major
- Lofexidine + Terazosin 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 Terazosin?
MediHelp rates the interaction as moderate. Diltiazem and Terazosin 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. Terazosin and diltiazem both lower blood pressure, so combined use can cause additive hypotension with dizziness or syncope. Diltiazem may also modestly raise exposure to some alpha-blockers through CYP3A4 inhibition.
How serious is the interaction between Diltiazem and Terazosin?
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 when starting or changing doses. Reduce the dose of either drug if symptomatic hypotension occurs.
What other medicines interact with Terazosin?
MediHelp also lists interactions of Terazosin with, for example, Alfuzosin, Amifostine, Avanafil. The full list is on the Terazosin page.
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