Drug interactions
Diltiazem + Nelfinavir
Severity: Moderate
Diltiazem and Nelfinavir: 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 and nelfinavir are both CYP3A4 substrates and inhibitors, so each can raise the other's concentrations. Higher diltiazem exposure can cause bradycardia, AV block and hypotension, while nelfinavir levels may also rise modestly.
What this interaction means in plain words
Diltiazem and Nelfinavir 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; Nelfinavir belongs to Anti Virals.
Why it happens
Mutual inhibition of CYP3A4-mediated metabolism, with the protease inhibitor being the stronger inhibitor of diltiazem clearance.
What to do
Monitor heart rate, PR interval and blood pressure, and reduce the diltiazem dose if bradycardia or hypotension develops. Watch for nelfinavir adverse effects such as gastrointestinal intolerance.
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 Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Other interactions of Nelfinavir
- Alfuzosin + Nelfinavir Contraindicated
- Avanafil + Nelfinavir Contraindicated
- Dronedarone + Nelfinavir Contraindicated
- Eletriptan + Nelfinavir Contraindicated
- Ergotamine + Nelfinavir Contraindicated
- Flibanserin + Nelfinavir Contraindicated
Frequently asked questions
Can I take Diltiazem with Nelfinavir?
MediHelp rates the interaction as moderate. Diltiazem and Nelfinavir 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 and nelfinavir are both CYP3A4 substrates and inhibitors, so each can raise the other's concentrations. Higher diltiazem exposure can cause bradycardia, AV block and hypotension, while nelfinavir levels may also rise modestly.
How serious is the interaction between Diltiazem and Nelfinavir?
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 heart rate, PR interval and blood pressure, and reduce the diltiazem dose if bradycardia or hypotension develops. Watch for nelfinavir adverse effects such as gastrointestinal intolerance.
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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