Diltiazem and Dexamethasone Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Diltiazem
Dexamethasone Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Reduced dilTIAZem exposure
Interaction Deep Dive
Avoid coadministration of dilTIAZem with any known CYP3A inducer when possible, and consider alternative therapy1. If concomitant use of dilTIAZem with a CYP3A inducer is necessary, closely monitor following initiation or discontinuation of the CYP3A inducer and adjust the dosage of dilTIAZem as necessary 2.
Why it happens (mechanism)
Induction of CYP3A-mediated metabolism of dilTIAZem
Literature reports
1 report — tap to read
a) Coadministration of rifAMPin (a strong CYP3A inducer) with dilTIAZem (a CYP3A substrate) lowered the dilTIAZem plasma concentrations to undetectable levels 1.
Common questions
Can I take Diltiazem and Dexamethasone Injection together?
Reduced dilTIAZem exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Diltiazem and Dexamethasone Injection interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Diltiazem or Dexamethasone Injection need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: Diltiazem HCl intravenous injection, diltiazem HCl intravenous injection. Exela Pharma Sciences LLC (per DailyMed), Lenoir, NC, 2021. DailyMed
- Lennep BW, Mack J, Poondru S, et al: Enzalutamide: understanding and managing drug interactions to improve patient safety and drug efficacy. Drug Saf 2024; 47(7):617-641. PubMed
Keep reading about Diltiazem
Keep reading about Dexamethasone Injection
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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