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Diltiazem

Diltiazem is a calcium channel blocker used to treat high blood pressure and chronic stable angina (chest pain) in oral extended-release forms, and to control certain fast heart rhythms in hospital-given injections.

Brand names CardizemCardizem CDCardizem LACartia XTDilacor XR +11 more
Drug classes Calcium Channel Antagonists
Rx Forms 4
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026 Content updated Oct 2, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 115 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

How we combine label and product data →
Diltiazem at a glance The quick version — the full detail is in the Patient Information Guide below.
Dr. Brian Staiger, PharmD, BCPS
The Pharmacist’s Take By · Clinical pharmacist · Written

Diltiazem is a long-familiar calcium channel blocker, on the market since the early 1980s and available generically, that relaxes blood vessels and slows the heart a little; by mouth it treats high blood pressure and chronic stable angina (chest pain brought on by exertion), and an IV form controls certain fast heart rhythms in hospital. Most people tolerate it well, and the side effects they notice are ankle swelling, headache, constipation or a stuffy nose. The main thing to watch is a heartbeat that runs too slow (dizziness, fainting), a risk that rises with beta-blockers or digoxin, plus new breathlessness if you already have heart failure.

Clinical pearls

  • Swallow extended-release diltiazem whole, never crushed, chewed or opened, so it keeps releasing slowly through the day.
  • Simvastatin and lovastatin build up with diltiazem and can damage muscle, so a dose limit or pravastatin may be needed.
  • Rarely it injures the liver early on or causes a blistering rash; report yellow eyes, dark urine or peeling skin.
  • Tell your surgeon and anesthesia team you take diltiazem, since anesthetics can lower blood pressure and heart rate more than usual.
How we write & review this content — our editorial policy →
How you get itPrescription only
Comes asExtended-release capsule, Extended-release tablet, Tablet +1
Earliest FDA record1982
Companies listing it with the FDA48
FDA label last updatedOct 13, 2025
FDA’s strongest warning (boxed)None on the label

Patient information guide — a plain-language walkthrough of Diltiazem, written from its FDA label.

What Diltiazem is used for

▾

Diltiazem has different approved uses depending on the product and route.

  • Oral extended-release capsules and tablets (including Cardizem LA, Matzim LA, Cartia, Cartia Xt and generics): treat high blood pressure, alone or with other blood pressure medicines.
  • Oral extended-release products: chronic stable angina (Cardizem LA and Matzim LA describe it as improving exercise tolerance).
  • Cartia, Cartia Xt and some generic extended-release capsules: also angina due to coronary artery spasm.
  • Intravenous diltiazem injection: temporary control of rapid ventricular rate in atrial fibrillation or atrial flutter.
  • Intravenous diltiazem injection: rapid conversion of paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm.

How Diltiazem works

▾

Diltiazem is a calcium channel blocker. It limits calcium entering heart and blood vessel muscle cells, so vessels relax and resistance to blood flow falls. That lowers blood pressure and widens the heart's own arteries, and it eases the heart's oxygen needs by slightly lowering heart rate and blood pressure during activity. It also slows electrical conduction through the heart.

Diltiazem dosage

▾

Oral extended-release diltiazem is generally taken by mouth once a day, with the dose adjusted to your needs. DILT-XR capsules are recommended in the morning on an empty stomach and should be swallowed whole. Diltiazem extended-release tablets can be taken without regard to food. The injection is given in a monitored healthcare setting. Follow your prescriber and product label, including for missed doses.

Dosing details from the FDA-approved label

From the Diltiazem prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.

  • Direct intravenous single injections (bolus) - initial dose
    • 0.25 mg/kg actual body weight as a bolus administered over 2 minutes (20 mg is a reasonable dose for the average patient)
    • Patients with low body weights should be dosed on a mg/kg basis. Some patients may respond to an initial dose of 0.15 mg/kg, although duration of action may be shorter; experience with this dose is limited.
  • Direct intravenous single injections (bolus) - second dose if response is inadequate
    • 0.35 mg/kg actual body weight administered over 2 minutes (25 mg is a reasonable dose for the average patient), given after 15 minutes
    • Subsequent intravenous bolus doses should be individualized for each patient.
  • Continuous intravenous infusion for continued reduction of heart rate (up to 24 hours) in atrial fibrillation or atrial flutter
    • Immediately following bolus of 20 mg (0.25 mg/kg) or 25 mg (0.35 mg/kg) and reduction of heart rate, begin infusion at 10 mg/h
    • Some patients may maintain response to an initial rate of 5 mg/h
    • Rate may be increased in 5 mg/h increments up to 15 mg/h as needed
    • Maximum: 15 mg/h; infusion may be maintained for up to 24 hours (infusion exceeding 24 hours and rates exceeding 15 mg/h are not recommended)
    • Dilute in Normal Saline, D5W, or D5W/0.45% NaCl; use within 24 hours and keep refrigerated until use.
Read the label’s full dosing text

DOSAGE AND ADMINISTRATION Hypertensive or anginal patients who are treated with other formulations of diltiazem can safely be switched to DILT-XR [Diltiazem Hydrochloride Extended-Release Capsules, USP (Once-a-day dosage)] at the nearest equivalent total daily dose. Subsequent titration to higher or lower doses may, however, be necessary and should be initiated as clinically indicated. Studies have shown a slight increase in the rate of absorption of DILT-XR [Diltiazem Hydrochloride Extended-Release Capsules, USP (Once-a-day dosage)], when ingested with a high-fat breakfast; therefore, administration in the morning on an empty stomach is recommended. Patients should be cautioned that the DILT-XR [Diltiazem Hydrochloride Extended-Release Capsules, USP (Once-a-day dosage)] should not be opened, chewed or crushed, and should be swallowed whole. Dosage Hypertension Dosages must be adjusted to each patient’s needs, starting with 180 mg or 240 mg once daily. Based on the antihypertensive effect, the dose may be adjusted as needed. Individual patients, particularly ≥60 years of age, may respond to a lower dose of 120 mg. The usual dosage range studied in clinical trials was 180 mg to 480 mg once daily. Current clinical experience with the 540 mg dose is limited; the dose may be increased to 540 mg with little or no increased risk of adverse reactions. Doses should not exceed 540 mg once daily. While a dose of DILT-XR [Diltiazem Hydrochloride Extended-Release Capsules, USP (Once-a-day dosage)] given once daily may produce an antihypertensive effect similar to the same total daily dose given in divided doses, individual dose adjustment may be needed. Dosage Angina Dosages for the treatment of angina should be adjusted to each patient’s needs, starting with a dose of 120 mg once daily, which may be titrated to doses of up to 480 mg once daily. When necessary, titration may be carried out over a 7 to 14 day period. Concomitant Use with Other Cardiovascular Agents Sublingual Nitroglycerin may be taken as required to abort acute anginal attacks during diltiazem hydrochloride therapy. Prophylactic Nitrate Therapy Diltiazem hydrochloride may be safely co-administered with short- and long-acting nitrates.

Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →

Diltiazem side effects

▾

Common side effects

  • Runny or stuffy nose (rhinitis)
  • Headache
  • Sore throat (pharyngitis)
  • Constipation
  • Increased cough
  • Swelling in the legs or ankles (peripheral edema)
  • Muscle aches
  • Nausea, vomiting or diarrhea

When to get medical help

  • Call your doctor if you notice a very slow heartbeat, fainting, or severe dizziness.
  • Get help right away for new or worsening shortness of breath or swelling, which can signal heart failure getting worse.
  • Report yellowing of the skin or eyes, dark urine, or unusual tiredness, which can signal liver problems.
  • Seek urgent care for a severe skin rash, blistering, or peeling, which can signal a serious skin reaction such as Stevens-Johnson syndrome.
  • Chest pain that is new or worsening, or a fast or irregular heartbeat, needs prompt medical attention.

In clinical trials of the extended-release capsules, the most common side effects were:

  • Runny or stuffy nose
  • Headache
  • Sore throat
  • Constipation
  • Increased cough
  • Swelling in the legs or ankles
  • Muscle aches
  • Diarrhea, nausea or vomiting

Call your doctor for a very slow heartbeat, fainting, worsening heart failure symptoms, signs of liver problems, or a severe skin rash.

Diltiazem warnings and precautions

▾
  • Slow heart rate and AV block: diltiazem can slow the heart and rarely cause heart block, especially in people with sick sinus syndrome or those taking beta-blockers or digoxin.
  • Heart failure: it can worsen in people with impaired heart function.
  • Liver injury: enzyme elevations and acute liver injury have occurred, usually early in treatment and reversible after stopping.
  • Severe skin reactions: Stevens-Johnson syndrome, toxic epidermal necrolysis and others have been reported.
  • Injection: can cause symptomatic low blood pressure and requires continuous monitoring.

Diltiazem interactions

▾

Diltiazem affects and is affected by many medicines, partly through the CYP3A4 enzyme system.

  • Beta-blockers and digoxin: added effects on heart conduction; propranolol and digoxin levels can change.
  • Clonidine: slow heartbeat has led to hospitalization.
  • Ivabradine: avoid together.
  • Simvastatin and lovastatin: levels rise, raising muscle damage risk.
  • Midazolam and triazolam: stronger, longer sedation.
  • Buspirone, carbamazepine, quinidine, cyclosporine: levels rise.
  • Cimetidine: raises diltiazem levels.
  • Rifampin: can lower diltiazem to undetectable levels.
  • Anesthetics: effects on the heart and blood vessels can be amplified.

Interactions listed in the FDA-approved label

From the Diltiazem prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.

  • Beta-blockers: Concomitant use is usually well tolerated, but there may be additive effects in prolonging AV conduction, and data are not sufficient to predict effects in patients with left ventricular dysfunction or cardiac conduction abnormalities. Caution and careful titration are warranted.
  • Propranolol: Propranolol levels increased in all five volunteers and its bioavailability increased approximately 50%. If combination therapy is initiated or withdrawn, an adjustment in the propranolol dose may be warranted.
  • Digitalis (digoxin): Plasma digoxin concentrations increased approximately 20% in 24 healthy males, though another investigator found no increase in 12 patients with coronary artery disease; additive effects in prolonging AV conduction are possible. Monitor digoxin levels when initiating, adjusting, and discontinuing diltiazem to avoid possible over- or under-digitalization.
  • Benzodiazepines (midazolam, triazolam): Diltiazem increased the AUC of midazolam and triazolam by 3- to 4-fold and the Cmax by 2-fold, and increased half-life 1.5- to 2.5-fold, which can increase clinical effects such as prolonged sedation.
  • Statins: Diltiazem, a CYP3A4 inhibitor, significantly increases the AUC of some statins, raising the risk of myopathy and rhabdomyolysis with statins metabolized by CYP3A4; simvastatin AUC increased 5-fold and lovastatin AUC and Cmax 3- to 4-fold, with no significant change for pravastatin. When possible, use a non-CYP3A4-metabolized statin. Otherwise reduce the dose of both and monitor for muscle toxicity; if simvastatin is required, limit simvastatin to 10 mg daily and diltiazem to 240 mg daily.
  • Rifampin (or any known CYP3A4 inducer): Coadministration lowered diltiazem plasma concentrations to undetectable levels. Avoid when possible and consider alternative therapy.
  • Ivabradine: Diltiazem increases exposure to ivabradine and may exacerbate bradycardia and conduction disturbances. Avoid concomitant use.
  • Cimetidine: Peak diltiazem plasma levels increased 58% and AUC 53% after a 1-week course of cimetidine 1200 mg/day with a single 60 mg diltiazem dose; ranitidine produced smaller, nonsignificant increases. Monitor for a change in pharmacological effect when starting or stopping cimetidine; a diltiazem dose adjustment may be warranted.
  • Cyclosporine: In transplant recipients a cyclosporine dose reduction of 15% to 48% was necessary to maintain similar trough concentrations after adding diltiazem. Monitor cyclosporine concentrations, especially when diltiazem is initiated, adjusted, or discontinued.
  • Carbamazepine: Elevated serum carbamazepine levels (40% to 72% increase), resulting in toxicity in some cases. Monitor patients for a potential drug interaction.
Read the label’s full interactions text

Drug Interactions Due to the potential for additive effects, caution and careful titration are 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 extended-release capsules (see WARNINGS ). As with all drugs, care should be exercised when treating patients with multiple medications. 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 the enzyme system may have a significant impact on the efficacy and side effect profile of diltiazem. Patients taking other drugs that are substrates of CYP450 3A4, especially patients with renal and/or hepatic impairment, may require dosage adjustment when starting or stopping concomitantly administered diltiazem in order to maintain optimum therapeutic blood levels. Anesthetics: The depression of cardiac contractility, conductivity, and automaticity as well as the vascular dilation associated with anesthetics may be potentiated by calcium channel blockers. When used concomitantly, anesthetics and calcium channel blockers should be titrated carefully. Benzodiazepines: Studies showed that diltiazem increased the AUC of midazolam and triazolam by 3- to 4-fold and the C max by 2-fold, compared to placebo. The elimination half-life of midazolam and triazolam also increased (1.5- to 2.5-fold) during coadministration with diltiazem. These pharmacokinetic effects seen during diltiazem coadministration can result in increased clinical effects (e.g., prolonged sedation) of both midazolam and triazolam.

Excerpted — the section continues on the label. Read the full Drug Interactions section on DailyMed →

Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.

🌿260 supplements and herbs with documented Diltiazem interactions, ranked by severity Check Diltiazem against a supplement or herb →

Before taking Diltiazem

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  • Heart failure, weak heart function, slow heart rate, sick sinus syndrome or heart block.
  • Liver problems; levels can be higher in cirrhosis.
  • Injection is contraindicated in severe low blood pressure, cardiogenic shock, ventricular tachycardia, and atrial fibrillation/flutter with an accessory pathway such as WPW, and should not be given with IV beta-blockers within a few hours.
  • Pregnancy: human data have not shown a drug-associated risk, but animal studies showed fetal harm.
  • Breastfeeding: diltiazem passes into breast milk.
  • Children: safety and effectiveness not established.
  • Older adults: dosing usually starts low.
  • Kidney impairment: the label says no dose adjustment is necessary.

Diltiazem overdose

▾

Overdose can cause a slow heart rate, low blood pressure, heart block and heart failure. Treatment is supportive and may include atropine, fluids, medicines to raise blood pressure, or cardiac pacing. Diltiazem does not appear to be removed by dialysis. Seek emergency help or call Poison Control right away for a suspected overdose.

What Diltiazem does in the body

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Diltiazem lowers peripheral vascular resistance and blood pressure, mainly in people who have high blood pressure. It slightly lowers resting heart rate and slows conduction through the AV node. In studies of the extended-release capsules, higher doses lowered blood pressure more and increased exercise time in people with chronic stable angina, with fewer angina attacks and less nitroglycerin use.

How your body processes Diltiazem

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Diltiazem is well absorbed from the gut, but the liver clears a large share before it reaches the bloodstream, so about 40% of an oral dose is available. It is heavily metabolized, and only 2% to 4% leaves unchanged in the urine. The half-life is about 3 to 4.5 hours, and about 6 to 9 hours for the extended-release tablets. People with cirrhosis had higher exposure, while severely impaired kidney function showed no difference in one small study.

How to store Diltiazem

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Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F) . Avoid excessive humidity and temperatures above 30°C (86°F). Dispense in tight, light resistant container as defined in USP.

Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

260

Supplements & herbs that interact with Diltiazem

260 supplements and herbal products have documented interactions with Diltiazem in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.

Severity mix
  • Major · 7
  • Moderate · 214
  • Minor · 39
ACTIVATED CHARCOAL Major AMERICAN HELLEBORE Major AMERICAN MISTLETOE Major COLEUS Major GRAPEFRUIT Major ST. JOHN'S WORT Major TYRAMINE Major ACACIA RIGIDULA Moderate +252 more
Every supplement checked against Diltiazem — ranked by severity The full interaction hub: 7 major · 214 moderate · 39 minor · every one linked to its full report. Check Diltiazem against your exact supplements

Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.

2

Nutrient depletion considerations

Diltiazem has been associated with lower levels of 2 nutrients in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.

COENZYME Q10 Insufficient Evidence VITAMIN C Insufficient Evidence
See the full Diltiazem nutrient depletion report

Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.

Diltiazem: pharmacist answers to common questions

Quick, plain-English answers to the questions patients ask most about Diltiazem — the kind of thing our pharmacy team would talk through with you at the counter.

What is diltiazem used for?

▾
The pills and capsules you take by mouth are used for high blood pressure and for chronic stable angina, which is chest pain from the heart's workload. Some capsule brands, such as Cartia, are also used for angina caused by coronary artery spasm. The injection is a hospital treatment for certain fast heart rhythms.

How should I take my extended-release capsule or tablet?

▾
Usually it's taken once a day, and you should swallow it whole. Don't open, chew or crush the capsules. Some products, like DILT-XR, are best taken in the morning on an empty stomach, while the extended-release tablets can be taken with or without food. Check your own label and ask me if you're unsure.

What side effects should I expect?

▾
The most common ones are a stuffy or runny nose, headache, sore throat, constipation, cough, and swelling in the legs or ankles. Most are mild. Call your doctor if you faint, feel a very slow heartbeat, have new shortness of breath or swelling, yellow skin or eyes, or a severe rash.

Can I take it with my other medicines?

▾
Diltiazem interacts with quite a few drugs, so always check with me first. Examples include beta-blockers, digoxin, clonidine, simvastatin, lovastatin, midazolam, triazolam, cyclosporine, carbamazepine and rifampin. Ivabradine should be avoided with it.

Is diltiazem safe in pregnancy or while breastfeeding?

▾
Decades of published human data haven't shown a drug-linked risk of birth defects, but animal studies showed harm to developing offspring at higher doses. Diltiazem does pass into breast milk, so talk with your doctor about the best plan for you and your baby.

Does it affect the liver?

▾
Rarely, yes. Liver enzyme increases and acute liver injury have been reported, usually in the first 1 to 8 weeks, and they improved after stopping. Tell your doctor if you notice yellow skin or eyes, dark urine, or unusual tiredness.

Is Diltiazem available over the counter?

▾
No. Diltiazem is a prescription medicine: every Diltiazem product listed with the FDA is prescription only, so it is not sold over the counter. Your prescriber decides whether it is appropriate for you, and your pharmacist dispenses it.

When was Diltiazem first available?

▾
The earliest FDA record we hold for Diltiazem is from 1982: its first approval in Drugs@FDA or its earliest product listing in the NDC Directory, whichever is older. Many older medicines were in use before their first formal FDA approval, so this is the earliest date on record, not necessarily when Diltiazem was first used.

Who makes Diltiazem?

▾
48 companies currently list Diltiazem products in the FDA's NDC Directory, including Bryant Ranch Prepack, Bausch Health US LLC, Oceanside Pharmaceuticals. That count includes repackagers and distributors as well as manufacturers (companies that sell only the raw ingredient are not counted), so fewer companies actually make it; the label on your bottle names the one that supplied yours.

Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

More about Diltiazem on HelloPharmacist

📊Diltiazem supplement interactions260 checked — ranked by severity 🌿Drug & Supplement CheckerDiltiazem vs. vitamins & herbs 💬Ask a PharmacistFree answer, usually < 24h 🔎NDC & pricing lookupFind Diltiazem NDCs & costs 🅰️Browse Drugs A–ZLook up any medication
Detailed data & references for Diltiazem Forms & strengths, pricing, billing codes, manufacturers, safety reports and sourcing — the data behind the page. Most people can stop here. Each section below opens on a tap.

Diltiazem forms and strengths (how it comes)

Diltiazem is available in 4 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Extended-release capsule

By mouth
Brands Cardizem CD Cartia Cartia Xt Tiazac
How this form is used
What it may be used for
  • Cartia and Cartia Xt are used for high blood pressure and for chronic stable angina and angina due to coronary artery spasm.
  • Diltiazem HCL ER is used for high blood pressure and for chronic stable angina and angina due to coronary artery spasm.
  • Diltiazem Hydrochloride Extended Release is used for high blood pressure and chronic stable angina.
Important instructions
  • Diltiazem Hydrochloride Extended Release capsules have dosing adjusted to each person, with usual hypertension starting doses taken once daily.
  • Diltiazem Hydrochloride Extended Release capsules reach their full blood pressure effect by about 14 days, so dose changes are timed accordingly.
Available strengths 8 strengths
60 mg 90 mg 120 mg 180 mg 240 mg 300 mg
Show 2 more strengths Show fewer strengths
360 mg 420 mg
463 FDA-listed product records ⓘ

Extended-release tablet

By mouth
Brands Cardizem LA
How this form is used
What it may be used for
  • Cardizem LA is used to lower high blood pressure and improve exercise tolerance in chronic stable angina.
  • Matzim LA is used to lower high blood pressure and improve exercise tolerance in chronic stable angina.
Important instructions
  • Diltiazem hydrochloride extended-release tablets can be taken without regard to food, based on a high-fat breakfast study.
Available strengths 6 strengths
120 mg 180 mg 240 mg 300 mg 360 mg 420 mg
87 FDA-listed product records ⓘ

Tablet

By mouth
Brands Cardizem
Available strengths 4 strengths
30 mg 60 mg 90 mg 120 mg
84 FDA-listed product records ⓘ

Injection

Into a vein
Brands Diltiazem Hci DILTIAZEM HYDROCHLORIDE in SODIUM CHLORIDE
How this form is used
What it may be used for
  • Diltiazem Hydrochloride Injection gives temporary control of rapid ventricular rate in atrial fibrillation or atrial flutter.
  • Diltiazem Hydrochloride Injection rapidly converts paroxysmal supraventricular tachycardia (PSVT) to normal rhythm.
  • Diltiazem Hydrochloride in Sodium Chloride Injection is used in adults for the same two heart rhythm uses.
Important instructions
  • Diltiazem Hydrochloride in Sodium Chloride Injection is given with ECG and blood pressure monitoring, with emergency equipment available.
  • Diltiazem Hydrochloride in Sodium Chloride Injection is ready to use and should not be mixed with other drugs.
Available strengths 3 strengths
1 mg/mL 5 mg/mL 100 mg
43 FDA-listed product records ⓘ

Diltiazem on the U.S. market: products, makers and brands

How Diltiazem appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

48 companies list 299 Diltiazem product records with the FDA, mostly as extended-release capsule, extended-release tablet, tablet; the earliest marketing or approval year on record is 1982. Brand names on the directory include Cardizem, Cardizem CD, Cardizem LA and 13 more; the rest are generics.

4
Dose forms ⓘ
48
Labelers (makers, repackagers, distributors)
15
Brand names
299
FDA-listed product records ⓘ
1982
Earliest FDA record ⓘ

FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

Also listed with the FDA, not a patient dose form: Powder (19) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.

Bryant Ranch Prepack10%
Bausch Health US LLC7%
Oceanside Pharmaceuticals7%
Sun Pharmaceutical Industries, Inc.5%
Zydus Lifesciences Limited5%
Alembic Pharmaceuticals Inc.4%
Other makers62%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

How widely Diltiazem is used (Medicaid data)

A general measure of how commonly Diltiazem is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Diltiazem is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

435,096
Medicaid prescriptions filled (Q1–Q4 2025)
$10.5M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Diltiazem prescribed? Of the 1,601 medications we measure, Diltiazem ranks #280 by Medicaid prescriptions — more than 83% of them.

Where Diltiazem ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5
Total prescriptions — #280 of 1,601
#275 Omega-3-Acid Ethyl Est... 450,937 Rx #276 Fentanyl 440,395 Rx #277 Formoterol / Mometason... 440,187 Rx #278 Ziprasidone 438,206 Rx #279 Ciclopirox Topical 437,507 Rx #280 Diltiazem 435,096 Rx #281 Warfarin 433,961 Rx #282 Acetaminophen, Butalbi... 425,589 Rx #283 Varenicline 417,684 Rx #284 Human Insulin Injectio... 414,373 Rx #285 Loperamide 409,237 Rx

Utilization by Diltiazem product

Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.

The 120 mg 24 hr extended release oral capsule is the most-dispensed Diltiazem product — about 30% of these Medicaid prescriptions.

24 HR diltiazem hydrochloride 120 MG Extended Release Oral Capsule Most dispensed

129,347 Medicaid prescriptions (Q1–Q4 2025) 30% of Diltiazem prescriptions shown $2.1M gross reimbursement (before rebates) ≈ $16 per prescription (gross)

Summed across the 23 of 140 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830861

24 HR diltiazem hydrochloride 240 MG Extended Release Oral Capsule

94,584 Medicaid prescriptions (Q1–Q4 2025) 22% of Diltiazem prescriptions shown $2.1M gross reimbursement (before rebates) ≈ $22 per prescription (gross)

Summed across the 22 of 133 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830837

24 HR diltiazem hydrochloride 180 MG Extended Release Oral Capsule

83,398 Medicaid prescriptions (Q1–Q4 2025) 19% of Diltiazem prescriptions shown $1.6M gross reimbursement (before rebates) ≈ $19 per prescription (gross)

Summed across the 22 of 138 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830845

diltiazem hydrochloride 30 MG Oral Tablet

29,299 Medicaid prescriptions (Q1–Q4 2025) 7% of Diltiazem prescriptions shown $371,221 gross reimbursement (before rebates) ≈ $13 per prescription (gross)

Summed across the 7 of 34 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 833217

24 HR diltiazem hydrochloride 360 MG Extended Release Oral Capsule

27,673 Medicaid prescriptions (Q1–Q4 2025) 6% of Diltiazem prescriptions shown $969,630 gross reimbursement (before rebates) ≈ $35 per prescription (gross)

Summed across the 6 of 64 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830795

diltiazem hydrochloride 60 MG Oral Tablet

17,520 Medicaid prescriptions (Q1–Q4 2025) 4% of Diltiazem prescriptions shown $267,414 gross reimbursement (before rebates) ≈ $15 per prescription (gross)

Summed across the 6 of 36 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 831103

diltiazem hydrochloride 120 MG Oral Tablet

15,443 Medicaid prescriptions (Q1–Q4 2025) 4% of Diltiazem prescriptions shown $281,937 gross reimbursement (before rebates) ≈ $18 per prescription (gross)

Summed across the 3 of 27 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 831054

24 HR diltiazem hydrochloride 300 MG Extended Release Oral Capsule

13,658 Medicaid prescriptions (Q1–Q4 2025) 3% of Diltiazem prescriptions shown $336,733 gross reimbursement (before rebates) ≈ $25 per prescription (gross)

Summed across the 8 of 83 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830801

12 HR diltiazem hydrochloride 120 MG Extended Release Oral Capsule

5,035 Medicaid prescriptions (Q1–Q4 2025) 1% of Diltiazem prescriptions shown $833,862 gross reimbursement (before rebates) ≈ $166 per prescription (gross)

Summed across the 5 of 16 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830872

diltiazem hydrochloride 90 MG Oral Tablet

4,689 Medicaid prescriptions (Q1–Q4 2025) 1% of Diltiazem prescriptions shown $92,069 gross reimbursement (before rebates) ≈ $20 per prescription (gross)

Summed across the 4 of 29 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 831102

12 HR diltiazem hydrochloride 60 MG Extended Release Oral Capsule

4,001 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $522,957 gross reimbursement (before rebates) ≈ $131 per prescription (gross)

Summed across the 5 of 15 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830865

24 HR diltiazem hydrochloride 240 MG Extended Release Oral Tablet

2,275 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $209,029 gross reimbursement (before rebates) ≈ $92 per prescription (gross)

Summed across the 6 of 15 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830879

24 HR diltiazem hydrochloride 120 MG Extended Release Oral Tablet

2,271 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $166,983 gross reimbursement (before rebates) ≈ $74 per prescription (gross)

Summed across the 5 of 10 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830874

24 HR diltiazem hydrochloride 180 MG Extended Release Oral Tablet

1,987 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $163,273 gross reimbursement (before rebates) ≈ $82 per prescription (gross)

Summed across the 5 of 13 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830877

24 HR diltiazem hydrochloride 360 MG Extended Release Oral Tablet

1,070 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $150,280 gross reimbursement (before rebates) ≈ $140 per prescription (gross)

Summed across the 5 of 13 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830897

5 ML diltiazem hydrochloride 5 MG/ML Injection

1,055 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $56,995 gross reimbursement (before rebates) ≈ $54 per prescription (gross)

Summed across the 3 of 15 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1791229

12 HR diltiazem hydrochloride 90 MG Extended Release Oral Capsule

888 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $134,952 gross reimbursement (before rebates) ≈ $152 per prescription (gross)

Summed across the 4 of 15 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830869

24 HR diltiazem hydrochloride 420 MG Extended Release Oral Capsule

628 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $29,712 gross reimbursement (before rebates) ≈ $47 per prescription (gross)

Summed across the 2 of 18 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 831359

24 HR diltiazem hydrochloride 300 MG Extended Release Oral Tablet

212 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $34,133 gross reimbursement (before rebates) ≈ $161 per prescription (gross)

Summed across the 5 of 12 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830882

diltiazem hydrochloride 100 MG Injection

39 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $15,332 gross reimbursement (before rebates) ≈ $393 per prescription (gross)

Summed across the 1 of 5 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1791240

24 HR diltiazem hydrochloride 420 MG Extended Release Oral Tablet

24 Medicaid prescriptions (Q1–Q4 2025) <1% of Diltiazem prescriptions shown $3,651 gross reimbursement (before rebates) ≈ $152 per prescription (gross)

Summed across the 2 of 12 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 830900

Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Diltiazem, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 149 of 843 listed Diltiazem NDCs with Medicaid activity.

Compare Diltiazem products

A representative set of FDA-listed product records for Diltiazem — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 101 of 299 products — FDA National Drug Code Directory. See every product, package size and price: browse all 299 Diltiazem NDCs →

Diltiazem recall history

A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.

The FDA’s enforcement reports list 7 Diltiazem recalls since July 2021, covering 9 product listings. Four of them are still ongoing or began in the last six months and are listed first. A recall names specific lots from one company, so check the lot number on your own bottle rather than assuming every product is affected; your pharmacist can check whether your supply came from an affected lot.

Ongoing Class II Mar 13, 2025 · Glenmark Pharmaceuticals Inc., USA
CGMP Deviations
  • Diltiazem Hydrochloride Extended-Release Capsules 12HR 120mg, 100-count bottle, Rx, Only. Manufactured by: Glenmark Pharmaceuticals Limited, Pithampur, Madhya Pradesh 454775, India, Manufactured for:… Lots: Lot # 17241067, exp. date May-26 17241628, exp. date Aug-26 FDA record D-0342-2025 →
Ongoing Class II Nov 1, 2024 · Glenmark Pharmaceuticals Inc., USA
cGMP Deviations: Presence of N-nitroso-Desmethyl-Diltiazem impurity above FDA recommended interim limit.
  • Diltiazem Hydrochloride Extended-Release Capsules, USP 120 mg, Rx Only, 100 Capsules, Manufactured for: Glenmark Pharmaceuticals Inc., USA, Mahwah, NJ 07430, Product of India, NDC 68462-562-01. Lots: Lot #: 17222470, 17230680, 17222547, Exp. Date 11/30/2024; 17230304, Exp. Date, 12/31/2024; 17230598, Exp. Date, 02/2025. FDA record D-0095-2025 →
  • Diltiazem Hydrochloride Extended-Release Capsules, USP 90 mg, Rx Only, 100 Capsules, Manufactured for : Glenmark Pharmaceuticals Inc., USA Mahwah, NJ 07430, Product of India, NDC 68462-851-01. Lots: Lot #s 17222452, Exp. Date, 11/30/2024; 17230607, Exp. Date 02/28/2025 FDA record D-0094-2025 →
  • Diltiazem Hydrochloride Extended-Release Capsules, USP 60 mg, Twice-a-Day Dosage, Rx Only, 100 Capsules per bottle, Manufactured for: Glenmark Pharmaceuticals Inc., USA Mahwah, NJ 07430, Product of I… Lots: Lot #s: 17222544, Exp. Date 11/30/2024 ; 17230784, Exp Date 03/31/2025; 17231080, Exp. Date 04/30/2025 FDA record D-0093-2025 →
Ongoing Class II Apr 17, 2024 · Glenmark Pharmaceuticals Inc., USA
Failed Dissolution Specifications
  • Diltiazem Hydrochloride Extended-Release Capsules, USP 120 mg, Twice-a-Day Dosage, 100 Capsules per bottle, Rx Only, Manufactured for: Glenmark Pharmaceuticals Inc., USA Mahwah, NJ, 07430, Product of… Lots: Lot #: 17221312, Exp. 5/31/2024 FDA record D-0472-2024 →
Ongoing Class II Mar 26, 2024 · Glenmark Pharmaceuticals Inc., USA
Failed Dissolution Specifications: Out of Specification (OOS) was reported in test of dissolution at the 12th month time point in long term stability study.
  • Diltiazem Hydrochloride Extended-Release Capsules, USP 120 mg, Twice-a-Day Dosage, 100 Capsules per bottle, Rx Only, Manufactured for: Glenmark Pharmaceuticals Inc., USA Mahwah, NJ, 07430, Product of… Lots: Lot #: 17230304, Exp. 12/31/2024. FDA record D-0430-2024 →
Class II Jan 13, 2023 · Terminated · SUN PHARMACEUTICAL INDUSTRIES INC
Failed Impurity (Deacetyl Diltiazem Hydrochloride) specification during stability testing and failed dissolution testing at FDA laboratory.
  • Diltiazem Hydrochloride Extended-Release Capsules, USP, 360 mg; Rx only; 90-count bottles, Manufactured by: Sun Pharmaceutical Industries Ltd. Halol-Baroda Highway, Halol-389350, Gujarat, India; Dist… Lots: Lot #: HAC3120A, HAC3121A, Exp. 04/2023; HAC4460A, Exp. 10/2023; HAD0365A, Exp. 12/2023; HAD1452A, Exp. 02/2024. FDA record D-0262-2023 →
Class II Jul 21, 2022 · Terminated · Teva Pharmaceuticals USA Inc
Failed Dissolution Specifications: below specification limits for dissolution.
  • Matzim LA (Diltiazem Hydrochloride) Extended-Release Tablets, 180 mg, 30-count bottle, Rx Only, Manufactured by: Actavis Laboratories FL, Inc., Fort Lauderdale, FL 33314, USA; Distributed by: Actavis… Lots: Lot 1411593A, Exp 09/22 FDA record D-1302-2022 →
Class II Oct 27, 2021 · Terminated · Teva Pharmaceuticals USA
Labelling: Incorrect Exp. Date
  • Cartia XT (Diltiazem Hydrochloride Extended-Release Capsules, USP) 120 mg, Rx Only, 90 capsules, labelled as (a) Manufactured By: Teva Pharmaceuticals USA, Inc., Parsippany, NJ 07054; (b) Manufacture… Lots: Lot # 100023805, Exp. Date 05/2023 FDA record D-0232-2022 →

Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Diltiazem RxCUI 3443 5 dose forms · 28 strengths
  1. Dose form (SCDF) Extended Release Oral Capsule RxCUI 374425 In current FDA listings
    Clinical drug / strength (SCD) 12 HR diltiazem hydrochloride 120 MG RxCUI 830872 12 HR diltiazem hydrochloride 60 MG RxCUI 830865 12 HR diltiazem hydrochloride 90 MG RxCUI 830869 24 HR diltiazem hydrochloride 120 MG RxCUI 830861 24 HR diltiazem hydrochloride 180 MG RxCUI 830845 24 HR diltiazem hydrochloride 240 MG RxCUI 830837 24 HR diltiazem hydrochloride 300 MG RxCUI 830801 24 HR diltiazem hydrochloride 360 MG RxCUI 830795 24 HR diltiazem hydrochloride 420 MG RxCUI 831359
  4. Dose form (SCDF) Oral Capsule RxCUI 393149 No current FDA listing
    Clinical drug / strength (SCD) hydrochloride 60 MG RxCUI 831012

Look up RxCUI 3443 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

Diltiazem brand names

Diltiazem is sold under 16 brand names in the FDA directory — Cardizem, Cardizem CD, Cardizem LA, Cartia XT and others. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.

Cardizem Cardizem CD Cardizem LA Cartia XT Dilacor XR Dilt-CD Diltzac Taztia XT Tiazac Cardizem SR Tiamate Matzim Tiadylt Taztia Dilt Cartia

Who makes Diltiazem: manufacturers and labelers

48 companies list Diltiazem products with the FDA. By number of product records, the largest are Bryant Ranch Prepack, Bausch Health US LLC, Oceanside Pharmaceuticals. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.

Bryant Ranch Prepack 31 Bausch Health US LLC 20 Oceanside Pharmaceuticals 20 Sun Pharmaceutical Industries, Inc. 15 Zydus Lifesciences Limited 15 Alembic Pharmaceuticals Inc. 12 Alembic Pharmaceuticals Limited 12 Zydus Pharmaceuticals (USA) Inc. 11 Actavis Pharma, Inc. 10 ScieGen Pharmaceuticals, Inc. 10 Golden State Medical Supply, Inc. 9 Slate Run Pharmaceuticals, LLC 9 Ingenus Pharmaceuticals, LLC 8 Upsher-Smith Laboratories, LLC 8 A-S Medication Solutions 7 American Health Packaging 6 Cipla USA, Inc. 6 Hikma Pharmaceuticals USA Inc. 6 Macleods Pharmaceuticals Limited 5 NCS HealthCare of KY, LLC dba Vangard Labs 5 Chartwell RX, LLC 4 Major Pharmaceuticals 4 Teva Pharmaceuticals USA, Inc. 4 Viona Pharmaceuticals Inc 4

…and 24 more on the FDA NDC directory.

Diltiazem drug class (RxNorm)

Diltiazem belongs to the Calcium Channel Blocker class.

Pharmacologic class Calcium Channel Blocker
Drug family (ATC) Muscle relaxants, Benzothiazepine derivatives
How it works Calcium Channel Antagonists, Cytochrome P450 3A4 Inhibitors

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

Sources for this Diltiazem page

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Oct 13, 2025
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Diltiazem.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Diltiazem after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
115
Finished products in the current FDA directory
299
Companies listing them (makers, repackagers, distributors)
48
FDA labeler codes behind them ⓘ
54
Linked representative label ⓘ
Oceanside Pharmaceuticals
Linked label effective
Oct 13, 2025
Composite sections available
24
Linked SPL Set ID
862d65cb-a732-4786-b569-bad2eaafddfd
Linked SPL Document ID
f51e2ce0-22dd-4a31-bab8-70b0b55864af
Open the linked representative label on DailyMed ↗

How this page is built

HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Oceanside Pharmaceuticals is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →