What it's used for
Diltiazem hydrochloride extended-release capsules are used for the treatment of hypertension, either alone or in combination with other blood pressure medications.
Source: U.S. FDA-approved prescribing information (openFDA).
Typical dosing
Patients can be switched to extended-release capsules at the nearest equivalent total daily dose, though higher doses may be needed for some patients.
Dosing shown here is the general FDA-labeled range. Your prescribing clinician determines the exact dose, form, and schedule for you — this is not a substitute for medical advice.
Boxed warning / key safety info
This medication prolongs AV node refractory periods and may rarely result in abnormally slow heart rates or heart block.
What it looks like
Illustrative only — appearance varies by manufacturer and strength. Photo credit: NLM Pillbox.
Common side effects
Common adverse reactions include those reported in angina and hypertension clinical trials, though serious adverse reactions are rare.
Covered strengths on the Tab $0 list
Covered at $0 with an active Tab membership when filled at a participating pharmacy nationwide or through mail order. A licensed clinician must prescribe the medication.
Related medications
Other heart, blood pressure & cholesterol medications covered at $0 with an active Tab membership.
Diltiazem cost without insurance
Cash prices for Diltiazem without insurance vary widely by pharmacy, strength and quantity — the same prescription can cost very different amounts at two pharmacies in the same town. That is the problem a membership solves.
Diltiazem is on Tab's covered $0 generic list. With an active Tab membership, every covered strength is $0 — not a percentage off, not a coupon that changes month to month — at participating pharmacies nationwide or through mail order. You do not need insurance, and Tab works whether or not you have a health plan.
Tab is a membership, not insurance. Covered medications require a prescription from a licensed clinician.
Diltiazem dosage and administration
Patients controlled on diltiazem alone or in combination with other medications may be switched to diltiazem hydrochloride extended-release capsules, USP at the nearest equivalent total daily dose. Higher doses of diltiazem hydrochloride extended-release capsules, USP may be needed in some patients. Monitor patients closely. Subsequent titration to higher or lower doses may be necessary. There is limited general clinical experience with doses above 360 mg, but doses to 540 mg have been studied in clinical trials. The incidence of side effects increases as the dose increases with first-degree AV block, dizziness, and sinus bradycardia bearing the strongest relationship to dose. Hypertension : Adjust dosage to individual patient needs.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Your prescribing clinician decides the exact dose, form and schedule for you — this is not medical advice.
Diltiazem side effects
Serious adverse reactions have been rare in studies carried out to date, but it should be recognized that patients with impaired ventricular function and cardiac conduction abnormalities have usually been excluded from these studies. The following table presents the most common adverse reactions reported in placebo-controlled angina and hypertension trials in patients receiving diltiazem hydrochloride extended-release capsules up to 360 mg with rates in placebo patients shown for comparison. In addition, the following events were reported infrequently (less than 1%) in angina or hypertension trials: Cardiovascular: Congestive heart failure, palpitations, syncope, ventricular extrasystoles.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. This is not a complete list. Report side effects to your clinician, and seek care for anything severe or unexpected.
Diltiazem drug interactions
Because of the potential for additive effects, slow titration is warranted in patients receiving diltiazem hydrochloride concomitantly with other agents known to affect cardiac contractility and/or conduction (see WARNINGS ). Pharmacologic studies indicate that there may be additive effects in prolonging AV conduction when using beta-blockers or digitalis concomitantly with diltiazem hydrochloride (see WARNINGS ). Diltiazem is both a substrate and an inhibitor of the cytochrome P450 3A4 enzyme system. Other drugs that are specific substrates, inhibitors, or inducers of this enzyme system may have a significant impact on the efficacy and side effect profile of diltiazem.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Tell your clinician and pharmacist about every medication, supplement and over-the-counter product you take.
Who should not take diltiazem
Diltiazem hydrochloride is contraindicated in (1) patients with sick sinus syndrome except in the presence of a functioning ventricular pacemaker, (2) patients with second- or third-degree AV block except in the presence of a functioning ventricular pacemaker, (3) patients with hypotension (less than 90 mm Hg systolic), (4) patients who have demonstrated hypersensitivity to the drug, and (5) patients with acute myocardial infarction and pulmonary congestion documented by x-ray on admission.
Excerpt from the FDA-approved prescribing information (openFDA), retrieved 2026-09-15. Whether this medication is appropriate for you is a clinical decision made by your prescribing clinician.
Common questions
Is diltiazem covered at $0 with Tab?
Yes. Diltiazem is on Tab's covered $0 generic list — every covered strength is $0 with an active membership, at participating pharmacies nationwide or by mail order.
Do I need insurance to get diltiazem through Tab?
No. Tab is a membership, not insurance. Covered medications are $0 with an active membership whether or not you have a health plan.
How do I get a diltiazem prescription with Tab?
Book a video visit with a licensed Tab clinician (unlimited visits are included with membership). If it's clinically appropriate, they send the prescription to your chosen participating pharmacy or by mail order.
How much does diltiazem cost without insurance?
Without insurance, retail cash prices for diltiazem vary by pharmacy, strength and quantity. Diltiazem is on Tab's covered $0 generic list, so every covered strength is $0 with an active Tab membership at participating pharmacies nationwide or by mail order.
What is the cheapest way to get diltiazem?
For medications on Tab's covered list, a Tab membership is the cheapest route: covered strengths of diltiazem are $0 with an active membership, and unlimited video visits with a licensed clinician are included, so the visit that produces the prescription is covered too.
What is the usual dose of diltiazem?
Patients controlled on diltiazem alone or in combination with other medications may be switched to diltiazem hydrochloride extended-release capsules, USP at the nearest equivalent total daily dose. Higher doses of diltiazem hydrochloride extended-release capsules, USP may be needed in some patients. Monitor patients closely. Subsequent titration to higher or lower doses may be necessary. (FDA-approved label, retrieved 2026-09-15. Your clinician sets your dose.)
What are the side effects of diltiazem?
Serious adverse reactions have been rare in studies carried out to date, but it should be recognized that patients with impaired ventricular function and cardiac conduction abnormalities have usually been excluded from these studies. (FDA-approved label, retrieved 2026-09-15.)
What interacts with diltiazem?
Because of the potential for additive effects, slow titration is warranted in patients receiving diltiazem hydrochloride concomitantly with other agents known to affect cardiac contractility and/or conduction (see WARNINGS ). Pharmacologic studies indicate that there may be additive effects in prolonging AV conduction when using beta-blockers or digitalis concomitantly with diltiazem hydrochloride (see WARNINGS ). (FDA-approved label, retrieved 2026-09-15. Tell your clinician about every medication and supplement you take.)
Diltiazem is $0 on the covered list
Members pay $0 for covered generics at participating pharmacies nationwide or by mail order — plus unlimited virtual primary care, urgent care and dermatology visits. No insurance needed.
Solo $49/mo · Family $119/mo for up to 4 people · Family+ $149/mo for up to 8
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