Medication·Interactions·Reviewed June 9, 2026
Diltiazem interactions.
Diltiazem has 8 documented interactions in the NutriStack database, including 1 flagged to avoid or as a serious conflict. The full interaction list is below. None of this is a substitute for your prescriber's advice.
Diltiazem at a glance.
A quick, data-grounded summary. The full tables are below.
Diltiazem has 8 documented interactions in the NutriStack database, including 1 flagged to avoid or as a serious conflict. The full interaction list is below. None of this is a substitute for your prescriber's advice.
Substances that interact with diltiazem.
Every supplement and medication in the NutriStack database with a documented interaction with this drug, highest-severity first. Open any pair for the mechanism and sources.
| Substance | Interaction | What happens |
|---|---|---|
| St. John's Wort | Conflict | St. John's Wort induces CYP3A4, reducing diltiazem plasma levels significantly. This can lead to uncontrolled hypertension or angina. |
| Berberine | Caution | Diltiazem is itself a moderate CYP3A4 inhibitor that depends on the same enzyme for clearance. Adding berberine, which inhibits CYP3A4, CYP2D6, and... details → |
| Garlic Extract | Caution | Aged garlic extract reduces systolic and diastolic blood pressure by about 8 and 5 mmHg in hypertensive patients. Combined with diltiazem's... details → |
| L-Theanine | Caution | L-Theanine modestly lowers stress-induced blood pressure increases and has mild relaxing effects on vascular tone. Layered on top of diltiazem's... |
| Magnesium Citrate | Caution | Magnesium is a physiologic calcium antagonist that lowers blood pressure by about 2/1.8 mmHg at supplemental doses and also blunts sinoatrial and... details → |
| Quercetin | Caution | Quercetin pretreatment in rabbits roughly doubled the oral bioavailability of diltiazem by inhibiting CYP3A4 and intestinal P-glycoprotein. While... |
| Resveratrol | Caution | Resveratrol is a mechanism-based inhibitor of CYP3A4 and a P-glycoprotein blocker. In rats, oral resveratrol increased diltiazem AUC and Cmax... |
| Taurine | Caution | Taurine produces small but consistent reductions in blood pressure (about 3-4 mmHg systolic in meta-analysis) and slows heart rate through autonomic... details → |
The full diltiazem profile.
Uses, typical dosing, side effects, and the cited evidence for this medication.
Common diltiazem questions.
Quick answers drawn from the tables above.
What interacts with Diltiazem?
In the NutriStack database, Diltiazem has 8 documented interactions. The most notable include St. John's Wort, Berberine, Garlic Extract, L-Theanine, and Magnesium Citrate. Check any specific combination before taking it and confirm with your prescriber.
Which substances should I avoid with Diltiazem?
Diltiazem is flagged against 1 substance in the database, including St. John's Wort. These pairings carry a higher risk and should be reviewed with a clinician before combining.
Is it safe to take St. John's Wort with Diltiazem?
NutriStack classifies the St. John's Wort and Diltiazem pairing as conflict: St. John's Wort induces CYP3A4, reducing diltiazem plasma levels significantly. This can lead to uncontrolled hypertension or angina. Avoid combining St. John's Wort with diltiazem. Always confirm with your prescriber.
Check your whole stack
See how diltiazem fits your supplements.
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