Drug interactions
Diltiazem + Tacrolimus
Severity: Major
Diltiazem and Tacrolimus: major interaction.
Last updated Sources: US FDA label
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 raises tacrolimus concentrations and can cause nephrotoxicity, neurotoxicity and other toxicity. It is sometimes used deliberately to reduce tacrolimus dose requirements.
What this interaction means in plain words
Diltiazem and Tacrolimus can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Diltiazem belongs to Cardiovascular; Tacrolimus belongs to Miscellaneous.
Why it happens
Diltiazem inhibits CYP3A4 and P-glycoprotein, decreasing tacrolimus clearance.
What to do
Monitor tacrolimus trough levels and renal function closely and reduce the tacrolimus dose when diltiazem is started; readjust after stopping it.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Other interactions of Tacrolimus
- Adenovirus types 4 and 7 live + Tacrolimus Contraindicated
- Bcg vaccine live + Tacrolimus Contraindicated
- Cidofovir + Tacrolimus Contraindicated
- Cyclosporin + Tacrolimus Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Tacrolimus Contraindicated
- Measles mumps and rubella vaccine live + Tacrolimus Contraindicated
Frequently asked questions
Can I take Diltiazem with Tacrolimus?
MediHelp rates the interaction as major. Diltiazem and Tacrolimus can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Diltiazem raises tacrolimus concentrations and can cause nephrotoxicity, neurotoxicity and other toxicity. It is sometimes used deliberately to reduce tacrolimus dose requirements.
How serious is the interaction between Diltiazem and Tacrolimus?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor tacrolimus trough levels and renal function closely and reduce the tacrolimus dose when diltiazem is started; readjust after stopping it.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
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