NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated July 13, 2026

Diltiazem

Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026

Diltiazem is a benzothiazepine-type non-dihydropyridine calcium channel blocker that affects both vascular smooth muscle and cardiac conduction tissue. It is used for hypertension, angina, and rate control in atrial fibrillation/flutter. Its dual action on vessels and the AV node makes it versatile.

Evidence tier
Strong
Indexed sources
10 2018–2024
Interactions
0
Category
Prescription
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Publication status

Exploratory record, not a reviewed medical publication.

See the editorial and medical-review policies for the publication gate.

This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.

In short

What the research says.

A quick, data-only summary. The full evidence, dosing, and sources are below.

Diltiazem is a benzothiazepine-type non-dihydropyridine calcium channel blocker that affects both vascular smooth muscle and cardiac conduction tissue. NutriStack rates the supporting evidence as strong. Common adult dosing is 120–360 mg daily (extended-release once daily; immediate-release 3–4 times daily) (as prescribed by your physician), though a prescriber sets the actual dose. This profile indexes 10 sources.

What it's good for
  • Effective blood pressure reduction2
  • Rate control in atrial fibrillation/flutter1,2
  • Angina relief including vasospastic (Prinzmetal) angina
  • Coronary vasodilation5
What to watch for
  • Bradycardia
  • Peripheral edema
  • Dizziness
  • Severe sinus bradycardia or sick sinus syndrome without pacemaker
  • Second- or third-degree AV block without pacemaker6

The bottom line

Evidence rating strong. Most-documented uses: effective blood pressure reduction, rate control in atrial fibrillation/flutter, angina relief including vasospastic (prinzmetal) angina. 10 sources indexed (2018–2024), with 0 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

Inhibits L-type calcium channels in both vascular smooth muscle and cardiac tissue. Causes vasodilation (reducing blood pressure), slows conduction through the AV node (rate control), and reduces myocardial contractility and oxygen demand. Also has coronary vasodilatory properties, making it effective for vasospastic angina.6,7

Class
Non-Dihydropyridine Calcium Channel Blocker
Absorption
Fat-soluble; take with food
Dosing

Dosing & protocol.

Common range
120–360 mg daily (extended-release once daily; immediate-release 3–4 times daily) (as prescribed by your physician)
Recommended form
Extended-release capsule or tablet preferred for hypertension; immediate-release or IV for acute rate control

Extended-release formulations can be taken with or without food; immediate-release absorption is not significantly affected by food

Safety

Full safety detail.

Side effects

  • Bradycardia
  • Peripheral edema
  • Dizziness
  • Headache
  • Constipation
  • Flushing
  • AV block (dose-dependent)

Contraindications

  • Severe sinus bradycardia or sick sinus syndrome without pacemaker
  • Second- or third-degree AV block without pacemaker6
  • Severe hypotension
  • Concurrent IV beta-blocker administration6
  • Acute myocardial infarction with pulmonary congestion1
  • Accessory bypass tract (WPW syndrome) with atrial fibrillation5
Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

5

Reference material

5
FAQ

Common questions.

Quick answers about Diltiazem, drawn from the data on this page.

What is Diltiazem?

Diltiazem is a benzothiazepine-type non-dihydropyridine calcium channel blocker that affects both vascular smooth muscle and cardiac conduction tissue. It is used for hypertension, angina, and rate control in atrial fibrillation/flutter. Its dual action on vessels and the AV node makes it versatile.

What is Diltiazem used for?

Commonly cited benefits of Diltiazem include: Effective blood pressure reduction; Rate control in atrial fibrillation/flutter; Angina relief including vasospastic (Prinzmetal) angina; Coronary vasodilation. NutriStack rates the overall evidence as strong.

What is a typical dose of Diltiazem?

A typical adult dose of Diltiazem is 120–360 mg daily (extended-release once daily; immediate-release 3–4 times daily) (as prescribed by your physician). The commonly recommended form is Extended-release capsule or tablet preferred for hypertension; immediate-release or IV for acute rate control. These are general ranges, not personalized advice; confirm the right dose with a clinician.

What are the side effects of Diltiazem?

Reported side effects include bradycardia, peripheral edema, dizziness, headache, constipation, flushing. This is educational information; check with a healthcare professional before use.

How strong is the evidence for Diltiazem?

NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.

Use this with your stack

Diltiazem in NutriStack.

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NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.