Cartia XT Diltiazem Hydrochloride 300 mg Capsule, Extended Release, 90-count — NDC 62037-600-90 (Billing 62037-0600-90)
This is a package of 90 capsules of Cartia XT Diltiazem Hydrochloride 300 mg Capsule, Extended Release from Actavis Pharma, Inc., marketed since Jul 1998 and currently FDA-listed; retail pharmacies pay about $0.3020 per capsule (NADAC).
Other active recalls for Diltiazem Hydrochloride (different manufacturers) — 6 · tap to view
Past resolved recalls for this product (1)
Identity & classification
Regulatory identifiers FDA, NLM and CMS codes for this package
Drug-database identifiers Medi-Span GPI and First Databank GCN / HICL / AHFS classification
- GSN (GCN sequence number): 016572
- GCN: 02325
- GPI-14 (Medi-Span): 34000010127050
- HICL (First Databank): 000182
- AHFS class code: 24:04.04.24
- RxCUI (RxNorm): 830801
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- FDA label on DailyMed · label index refreshed Oct 1, 2026
- RxNorm (NLM RxNav) · catalog refreshed Oct 1, 2026
- Medi-Span GPI (licensed)
- First Databank (licensed) · refreshed Oct 1, 2026
RxNorm drug class
This medicine belongs to the Calcium Channel Blocker class.
Where does this data come from?
- RxClass (NLM) · catalog refreshed Oct 1, 2026
Clinical
Diltiazem is used to treat high blood pressure and to control angina (chest pain). Diltiazem is in a class of medications called calcium-channel blockers. It works by relaxing the blood vessels so the heart does not have to pump as hard. It also increases the supply of blood and oxygen to the heart. High blood pressure is a common condition, and when not treated it can cause damage to the brain, heart, blood vessels, kidneys, and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In...
Read the full MedlinePlus article ↗- 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...
- 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 stoma...
- How should I take my extended-release capsule or tablet?
- 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...
Patient education
Supplement & herbal interactions
Diltiazem may be associated with lower levels of 2 nutrients — worth a chat with your pharmacist, not a cause for alarm.
Where does this data come from?
- MedlinePlus (NLM) · refreshed Oct 1, 2026
- FDA label on DailyMed · label index refreshed Oct 1, 2026
Ask a licensed pharmacist directly — free, answered by our team.
Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $0.302 | $27.18 / 90 capsules |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $0.5204 | $46.84 / 90 capsules |
Where does this data come from?
- CMS NADAC weekly file · file of Sep 30, 2026
- CMS ASP pricing files · refreshed Sep 20, 2026
- CMS Medicaid State Drug Utilization Data · refreshed Oct 3, 2026
- CMS Part D plan pricing files · refreshed Sep 24, 2026
- VA National Acquisition Center price file
Packaging — all sizes for this product
| Package NDC | Description | Per unit | Per pack | Marketing start | Marketing end | Status |
|---|---|---|---|---|---|---|
| 62037-0600-05 62037-600-05 Main listing | 500 CAPSULE, EXTENDED RELEASE in 1 BOTTLE | $0.3020 / ea | $150.98 | 1999-06-23 | — | Active |
| 62037-0600-90 You're viewing this | 90 CAPSULE, EXTENDED RELEASE in 1 BOTTLE | $0.3020 / ea | $27.18 | 1999-06-23 | — | Active |
You're viewing the smallest of 2 pack sizes for this product.
This pack effectively ties for the lowest per-ea cost of the 2 priced pack sizes ($0.3020 NADAC).
This pack shows little to no recent Medicaid volume — the 500 capsules pack carries most fills. See all packs ↓
Pack size FAQ
What quantity is in this package?
How does this package differ from NDC 62037-0600-05?
What NDC number is used to bill for this package of Cartia XT Diltiazem Hydrochloride 300 mg Capsule, Extended Release?
Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.
Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Diltiazem Hydrochloride 300 mg 68682-0998-98 | OCEANSIDE | 90 capsules | $0.287 | AB3 | FDA listed | save 5% |
| Diltiazem Hydrochloride 300 mg 00904-7220-61 | Major | 1 capsule | $0.302 | AB3 | Availability likely | — |
| Diltiazem Hydrochloride Extended-Release 300 mg 10370-0832-05 | Endo | 500 capsules | $0.302 | AB3 | Discontinued | — |
| Diltiazem Hydrochloride 300 mg 24979-0029-02 | Upsher-Smith | 500 capsules | $0.302 | AB3 | Availability likely | — |
| Diltiazem Hydrochloride Extended-Release 300 mg 60687-0228-01 | American | 1 capsule | $0.302 | AB3 | Availability likely | — |
| Cartia XT 300 mgthis 62037-0600-90 | Actavis | 90 capsules | $0.302 | AB3 | Availability likely | — |
| Diltiazem hydrochloride 300 mg 63304-0721-05 | Sun | 500 capsules | $0.309 | — | FDA listed | +2% |
| Diltiazem Hydrochloride 300 mg 47335-0672-13 | Sun | 500 capsules | $0.516 | — | FDA listed | +71% |
| Diltiazem Hydrochloride EXTENDED RELEASE 300 mg 68682-0370-90 | Oceanside | 90 capsules | $0.516 | AB4 | FDA listed | +71% |
| Cardizem CD 300 mg 00187-0798-30 | Bausch | 30 capsules | — | AB3 | FDA listed | — |
| Tiazac Extended Release 300 mg 00187-2615-30 | Bausch | 30 capsules | — | AB4 | FDA listed | — |
| Diltiazem Hydrochloride 300 mg 33342-0524-02 | Macleods | 6 capsules | — | AB3 | FDA listed | — |
| Diltiazem Hydrochloride 300 mg 46708-0728-30 | Alembic | 30 capsules | — | AB3 | FDA listed | — |
| Diltiazem Hydrochloride 300 mg 47335-0678-13 | Sun | 500 capsules | — | — | FDA listed | — |
| diltiazem hydrochloride 300 mg 50742-0251-05 | Ingenus | 500 capsules | — | AB3 | FDA listed | — |
| Diltiazem Hydrochloride 300 mg 51407-0476-90 | Golden | 90 capsules | — | AB3 | FDA listed | — |
| Diltiazem Hydrochloride 300 mg 62332-0728-30 | Alembic | 30 capsules | — | AB3 | FDA listed | — |
| Diltiazem Hydrochloride Extended-Release 300 mg 63629-2159-01 | Bryant | 30 capsules | — | AB3 | FDA listed | — |
| diltiazem hydrochloride 300 mg 68382-0598-01 | Zydus | 100 capsules | — | AB3 | FDA listed | — |
| Tiadylt Er 300 mg 68382-0748-01 | Zydus | 100 capsules | — | AB4 | FDA listed | — |
| diltiazem hydrochloride 300 mg 70771-1033-01 | Zydus | 100 capsules | — | AB3 | FDA listed | — |
| Tiadylt Er 300 mg 70771-1038-00 | Zydus | 1000 capsules | — | AB4 | FDA listed | — |
| Cartia Xt 300 mg 72189-0344-90 | DirectRx | 90 capsules | — | AB3 | FDA listed | — |
| Diltiazem HCL ER 300 mg 72189-0409-90 | Direct_Rx | 90 capsules | — | AB3 | FDA listed | — |
| diltiazem hydrochloride 300 mg 84677-0042-90 | Golden | 90 capsules | — | AB3 | FDA listed | — |
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- FDA Orange Book · refreshed Sep 3, 2026
- CMS NADAC weekly file · file of Sep 30, 2026
Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
Where does this data come from?
- FDA Orange Book · refreshed Sep 3, 2026
What it looks like
Where does this data come from?
- FDA label on DailyMed · label index refreshed Oct 1, 2026
Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
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UNII 0ZBX0N59RZ
A plasticizer derived from citric acid that is added to tablet coatings and film formulations. It increases flexibility and durability of the coating layer, helping the tablet withstand handling and moisture without cracking.
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UNII 161H3B14U2
A synthetic plastic polymer used as an enteric coating on tablets and capsules. It dissolves in the intestines rather than the stomach, controlling where and when the medicine is released in the digestive tract.
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UNII 767IP0Y5NH
A synthetic red colorant used to give medicines their color. It helps patients identify their medication and makes the product visually appealing.
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UNII 35SW5USQ3G
A synthetic yellow dye used to color medicines. It helps make tablets, capsules, and liquids visually distinct so patients can easily identify their medication.
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UNII 3DYK7UYZ62
Ethylcellulose is a plant-fiber derivative used as a binder and film-coating agent in tablets and capsules. It helps hold ingredients together and can create a protective coating that controls how quickly the medicine dissolves.
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UNII H3R47K3TBD
FD&C Blue No. 1 is a synthetic blue dye approved for use in foods and medicines. It serves as a colorant to give the medication its distinctive appearance and help with product identification.
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UNII L06K8R7DQK
A synthetic blue dye approved by the FDA for use in medications and foods. It serves as a colorant to make pills and liquids visually distinct and easier to identify.
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UNII WZB9127XOA
A synthetic red dye used to color medications and make them easier to identify. It serves as a colorant in tablets, capsules, and liquid formulations.
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UNII 2G86QN327L
Gelatin is a protein derived from animal collagen, commonly used in medicines as a gelling agent and capsule material. It helps create soft or hard capsule shells that hold and release medication, and can also thicken liquid formulations.
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UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
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UNII 5KY68S2577
A synthetic plastic polymer made from two chemical compounds combined in a specific ratio. It forms a coating on tablets and capsules to control how and where the medication dissolves in the digestive tract.
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UNII 6OZP39ZG8H
Polysorbate 80 is a synthetic emulsifier derived from sorbitol and oleic acid. It helps mix oil and water-based ingredients together in medications and improves how the product disperses in the body.
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UNII 6DC9Q167V3
Propylene glycol is a clear liquid derived from petroleum or vegetable sources. It acts as a solvent, humectant, and preservative in medicines, helping dissolve active ingredients and maintain product stability.
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UNII O8232NY3SJ
A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
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UNII C151H8M554
A natural sugar derived from sugar cane or sugar beets. It's used as a sweetener, filler, and binder to improve taste, add bulk, and help hold tablet or capsule ingredients together.
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UNII 7SEV7J4R1U
A powder made from a naturally occurring mineral. In medicines, talc works as a glidant and anti-caking agent, helping tablets and capsules flow smoothly during manufacturing and preventing clumping.
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UNII 15FIX9V2JP
Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.
17 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.- FDA label on DailyMed · label index refreshed Oct 1, 2026
- FDA openFDA NDC Directory · synced Oct 1, 2026
Inactive ingredient FAQ
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Manufacturer & labeler
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- Drugs@FDA
Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS AND USAGE Diltiazem hydrochloride extended-release capsules (once-a-day dosage) are indicated for the treatment of hypertension. It may be used alone or in combination with other antihypertensive medications. Diltiazem hydrochloride extended-release capsules (once-a-day dosage) are indicated for the management of chronic stable angina and angina due to coronary artery spasm.
⏱️ Dosage and Administration ▾
DOSAGE AND ADMINISTRATION Patients controlled on diltiazem alone or in combination with other medications may be switched to diltiazem hydrochloride extended-release capsules (once-a-day dosage) at the nearest equivalent total daily dose. Higher doses of diltiazem hydrochloride extended-release capsules (once-a-day dosage) 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. When used as monotherapy, reasonable starting doses are 180 to 240 mg once daily, although some patients may respond to lower doses. Maximum antihypertensive effect is usually observed by 14 days of chronic therapy; therefore, schedule dosage adjustments accordingly.
The usual dosage range studied in clinical trials was 240 to 360 mg once daily. Individual patients may respond to higher doses of up to 480 mg once daily. Angina : Dosages for the treatment of angina should be adjusted to each patient’s needs, starting with a dose of 120 or 180 mg once daily.
Individual patients may respond to higher 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 NTG: May be taken as required to abort acute anginal attacks during diltiazem hydrochloride therapy.
Prophylactic Nitrate Therapy: Diltiazem hydrochloride may be safely coadministered with short- and long-acting nitrates. Beta-blockers: (see WARNINGS and PRECAUTIONS ) . Antihypertensives: Diltiazem hydrochloride has an additive antihypertensive effect when used with other antihypertensive agents.
Therefore, the dosage of diltiazem hydrochloride or the concomitant antihypertensives may need to be adjusted when adding one to the other.
⛔ Contraindications ▾
CONTRAINDICATIONS Diltiazem hydrochloride extended-release capsules (once-a-day dosage) are 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.
⚠️ Warnings ▾
WARNINGS Cardiac Conduction: Diltiazem hydrochloride prolongs AV node refractory periods without significantly prolonging sinus node recovery time, except in patients with sick sinus syndrome. This effect may rarely result in abnormally slow heart rates (particularly in patients with sick sinus syndrome) or second- or third-degree AV block (13 of 3290 patients or 0.40%). Concomitant use of diltiazem with beta-blockers or digitalis may result in additive effects on cardiac conduction.
A patient with Prinzmetal’s angina developed periods of asystole (2 to 5 seconds) after a single dose of 60 mg of diltiazem (see ADVERSE REACTIONS ). Congestive Heart Failure: Although diltiazem has a negative inotropic effect in isolated animal tissue preparations, hemodynamic studies in humans with normal ventricular function have not shown a reduction in cardiac index nor consistent negative effects on contractility (dP/dt). An acute study of oral diltiazem in patients with impaired ventricular function (ejection fraction 24% ± 6%) showed improvement in indices of ventricular function without significant decrease in contractile function (dP/dt).
Worsening of congestive heart failure has been reported in patients with preexisting impairment of ventricular function. Experience with the use of diltiazem hydrochloride in combination with beta-blockers in patients with impaired ventricular function is limited. Caution should be exercised when using this combination.
Hypotension: Decreases in blood pressure associated with diltiazem hydrochloride therapy may occasionally result in symptomatic hypotension. Acute Hepatic Injury: Mild elevations of transaminases with and without concomitant elevation in alkaline phosphatase and bilirubin have been observed in clinical studies. Such elevations were usually transient and frequently resolved even with continued diltiazem treatment.
In rare instances, significant elevations in enzymes such as alkaline phosphatase, LDH, SGOT, SGPT, and other phenomena consistent with acute hepatic injury have been noted. These reactions tended to occur early after therapy initiation (1 to 8 weeks) and have been reversible upon discontinuation of drug therapy. The relationship to diltiazem hydrochloride is uncertain in some cases, but probable in some (see PRECAUTIONS ).
🤒 Adverse Reactions ▾
ADVERSE REACTIONS 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 capsule (once-a-day dosage) up to 360 mg with rates in placebo patients shown for comparison.
Diltiazem Hydrochloride Extended-release Capsule (once-a-day dosage) Placebo-Controlled Angina and Hypertension Trials Combined Adverse Reactions Diltiazem Hydrochloride Extended-release Capsule (once-a-day dosage) (n=607) Placebo (n=301) Headache 5.4% 5.0% Dizziness 3.0% 3.0% Bradycardia 3.3% 1.3% AV Block First Degree 3.3% 0.0% Edema 2.6% 1.3% Asthenia 1.8% 1.7% In addition, the following events were reported infrequently (less than 1%) in angina or hypertension trials: Cardiovascular: Congestive heart failure, palpitations, syncope, ventricular extrasystoles.
Nervous System: Abnormal dreams, amnesia, depression, gait abnormality, hallucinations, insomnia, nervousness, paresthesia, personality change, somnolence, tinnitus, tremor. Gastrointestinal: Anorexia, constipation, diarrhea, dry mouth, dysgeusia, dyspepsia, mild elevations of SGOT, SGPT, LDH, and alkaline phosphatase (see WARNINGS , Acute Hepatic Injury ), thirst, vomiting, weight increase. Dermatological: Petechiae, photosensitivity, pruritus, urticaria.
Other: Amblyopia, CPK increase, dyspnea, epistaxis, eye irritation, hyperglycemia, hyperuricemia, impotence, muscle cramps, nasal congestion, nocturia, osteoarticular pain, polyuria, sexual difficulties. The following postmarketing events have been reported infrequently in patients receiving diltiazem hydrochloride: acute generalized exanthematous pustulosis, allergic reactions, alopecia, angioedema (including facial or periorbital edema), asystole, erythema multiforme (including Stevens-Johnson syndrome, toxic epidermal necrolysis), exfoliative dermatitis, extrapyramidal symptoms, gingival hyperplasia, hemolytic anemia, increased bleeding time, leukopenia, photosensitivity (including lichenoid keratosis and hyperpigmentation at sun-exposed skin areas), purpura, retinopathy, myopathy, and thrombocytopenia.
In addition, events such as myocardial infarction have been observed which are not readily distinguishable from the natural history of the disease in these patients. A number of well-documented cases of generalized rash, some characterized as leukocytoclastic vasculitis, have been reported. However, a definitive cause and effect relationship between these events and diltiazem hydrochloride therapy is yet to be established.
To report SUSPECTED ADVERSE REACTIONS, contact Teva at 1-888-838-2872 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
🔄 Drug Interactions ▾
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 extended-release capsules (once-a-day dosage) (see WARNINGS ). Diltiazem is both a substrate and an inhibitor of the Pg-p and cytochrome P450 3A4 enzyme system which may affect exposure to diltiazem and concomitant drugs metabolized by those pathways.
Patients with renal and/or hepatic impairment may be particularly at risk of exposure changes. 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, titrate anesthetics and calcium blockers slowly.
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.
Beta-blockers: Controlled and uncontrolled domestic studies suggest that concomitant use of diltiazem hydrochloride and beta-blockers is usually well tolerated, but available data are not sufficient to predict the effects of concomitant treatment in patients with left ventricular dysfunction or cardiac conduction abnormalities. Administration of diltiazem hydrochloride concomitantly with propranolol in five normal volunteers resulted in increased propranolol levels in all subjects and bioavailability of propranolol was increased approximately 50%.
In vitro , propranolol appears to be displaced from its binding sites by diltiazem. If combination therapy is initiated or withdrawn in conjunction with propranolol, an adjustment in the propranolol dose may be warranted (see WARNINGS ). Buspirone: In nine healthy subjects, diltiazem significantly increased the mean buspirone AUC 5.5-fold and C max 4.1-fold compared to placebo.
The T 1/2 and T max of buspirone were not significantly affected by diltiazem. Enhanced effects and increased toxicity of buspirone may be possible during concomitant administration with diltiazem. Subsequent dose adjustments may be necessary during coadministration, and should be based on clinical assessment.
Carbamazepine: Concomitant administration of diltiazem with carbamazepine has been reported to result in elevated serum levels of carbamazepine (40% to 72% increase), resulting in toxicity in some cases. Cimetidine: A study in six healthy volunteers has shown a significant increase in peak diltiazem plasma levels (58%) and AUC (53%) after a 1-week course of cimetidine at 1200 mg per day and a single dose of diltiazem 60 mg. Ranitidine produced smaller, nonsignificant increases.
The effect may be mediated by cimetidine’s known inhibition of hepatic cytochrome P450, the enzyme system responsible for the first-pass metabolism of diltiazem. Patients currently receiving diltiazem therapy should be carefully monitored for a change in pharmacological effect when initiating and discontinuing therapy with cimetidine. An adjustment in the diltiazem dose may be warranted.
Clonidine: Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concurrently with diltiazem. Monitor heart rate in patients receiving concomitant diltiazem and clonidine. Cyclosporine: A pharmacokinetic interaction between diltiazem and cyclosporine has been observed during studies involving renal and cardiac trans… [Excerpted — this section continues on DailyMed.]
🤰 Pregnancy ▾
Pregnancy Reproduction studies have been conducted in mice, rats, and rabbits. Administration of doses ranging from five to ten times greater (on a mg/kg basis) than the daily recommended therapeutic dose has resulted in embryo and fetal lethality. These doses, in some studies, have been reported to cause skeletal abnormalities.
In the perinatal/postnatal studies, there was an increased incidence of stillbirths at doses of 20 times the human dose or greater. There are no well-controlled studies in pregnant women; therefore, use diltiazem hydrochloride in pregnant women only if the potential benefit justifies the potential risk to the fetus.
🧒 Pediatric Use ▾
Pediatric Use Safety and effectiveness in pediatric patients have not been established.
🧓 Geriatric Use ▾
Geriatric Use Clinical studies of diltiazem did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
🆘 Overdosage ▾
OVERDOSAGE The oral LD 50 ’s in mice and rats range from 415 to 740 mg/kg and from 560 to 810 mg/kg, respectively. The intravenous LD 50 ’s in these species were 60 and 38 mg/kg, respectively. The oral LD 50 in dogs is considered to be in excess of 50 mg/kg, while lethality was seen in monkeys at 360 mg/kg.
The toxic dose in man is not known. Because of its extensive metabolism, blood levels after a standard dose of diltiazem can vary over tenfold, limiting the usefulness of blood levels in overdose cases. There have been reports of diltiazem overdose in amounts ranging from <1 g to 18 g.
Of cases with known outcome, most patients recovered and in cases with a fatal outcome, the majority involved multiple drug ingestion. Events observed following diltiazem overdose included bradycardia, hypotension, heart block, and cardiac failure. Most reports of overdose described some supportive medical measure and/or drug treatment.
Bradycardia frequently responded favorably to atropine, as did heart block, although cardiac pacing was also frequently utilized to treat heart block. Fluids and vasopressors were used to maintain blood pressure and in cases of cardiac failure, inotropic agents were administered. In addition, some patients received treatment with ventilatory support, gastric lavage, activated charcoal, and/or intravenous calcium.
In the event of overdose or exaggerated response, appropriate supportive measures should be employed in addition to gastrointestinal decontamination. Diltiazem does not appear to be removed by peritoneal or hemodialysis. Limited data suggest that plasmapheresis or charcoal hemoperfusion may hasten diltiazem elimination following overdose.
Based on the known pharmacological effects of diltiazem and/or reported clinical experiences, the following measures may be considered: Bradycardia: Administer atropine (0.60 to 1.0 mg). If there is no response to vagal blockade, administer isoproterenol cautiously. High-degree AV Block: Treat as for bradycardia above.
Fixed high-degree AV block should be treated with cardiac pacing. Cardiac Failure: Administer inotropic agents (isoproterenol, dopamine, or dobutamine) and diuretics. Hypotension: Vasopressors (e.g., dopamine or norepinephrine).
Actual treatment and dosage should depend on the severity of the clinical situation and the judgment and experience of the treating physician.
🧬 Clinical Pharmacology ▾
CLINICAL PHARMACOLOGY The therapeutic effects of diltiazem are believed to be related to its ability to inhibit the cellular influx of calcium ions during membrane depolarization of cardiac and vascular smooth muscle. Mechanisms of Action Hypertension: Diltiazem produces its antihypertensive effect primarily by relaxation of vascular smooth muscle and the resultant decrease in peripheral vascular resistance. The magnitude of blood pressure reduction is related to the degree of hypertension; thus hypertensive individuals experience an antihypertensive effect, whereas there is only a modest fall in blood pressure in normotensives.
Angina: Diltiazem has been shown to produce increases in exercise tolerance, probably due to its ability to reduce myocardial oxygen demand. This is accomplished via reductions in heart rate and systemic blood pressure at submaximal and maximal workloads. Diltiazem has been shown to be a potent dilator of coronary arteries, both epicardial and subendocardial.
Spontaneous and ergonovine-induced coronary artery spasms are inhibited by diltiazem. In animal models, diltiazem interferes with the slow inward (depolarizing) current in excitable tissue. It causes excitation-contraction uncoupling in various myocardial tissues without changes in the configuration of the action potential.
Diltiazem produces relaxation of coronary vascular smooth muscle and dilation of both large and small coronary arteries at drug levels that cause little or no negative inotropic effect. The resultant increases in coronary blood flow (epicardial and subendocardial) occur in ischemic and nonischemic models and are accompanied by dose-dependent decreases in systemic blood pressure and decreases in peripheral resistance. Hemodynamic and Electrophysiologic Effects Like other calcium channel antagonists, diltiazem decreases sinoatrial and atrioventricular conduction in isolated tissues and has a negative inotropic effect in isolated preparations.
In the intact animal, prolongation of the AH interval can be seen at higher doses. In man, diltiazem prevents spontaneous and ergonovine-provoked coronary artery spasm. It causes a decrease in peripheral vascular resistance and a modest fall in blood pressure in normotensive individuals and, in exercise tolerance studies in patients with ischemic heart disease, reduces the heart rate-blood pressure product for any given workload.
Studies, primarily in patients with good ventricular function, have not revealed evidence of a negative inotropic effect; cardiac output, ejection fraction, and left ventricular end diastolic pressure have not been affected. Such data have no predictive value with respect to effects in patients with poor ventricular function, and increased heart failure has been reported in patients with preexisting impairment of ventricular function. There are few data on the interaction of diltiazem and beta-blockers in patients with poor ventricular function.
Resting heart rate is usually slightly reduced by diltiazem. In hypertensive patients, diltiazem hydrochloride extended-release capsules (once-a-day dosage) produces antihypertensive effects both in the supine and standing positions. In a double-blind, parallel, dose-response study utilizing doses ranging from 90 to 540 mg once daily, diltiazem hydrochloride extended-release capsules (once-a-day dosage) lowered supine diastolic blood pressure in an apparent linear manner over the entire dose range studied.
The changes in diastolic blood pressure, measured at trough, for placebo, 90 mg, 180 mg, 360 mg, and 540 mg were –2.9, –4.5, –6.1, –9.5, and –10.5 mm Hg, respectively. Postural hypotension is infrequently noted upon suddenly assuming an upright position. No reflex tachycardia is associated with the chronic antihypertensive effects.
Diltiazem hydrochloride extended-release capsules (once-a-day dosage) decreases vascular resistance, increases cardiac output (by increasing stroke volume), and produces a slight decrease or no… [Excerpted — this section continues on DailyMed.]
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED Diltiazem hydrochloride extended-release capsules, USP (Once-a-day dosage) Strength Quantity NDC Number Description 120 mg 90’s 500’s 62037-597-90 62037-597-05 White/orange opaque capsule imprinted with "Andrx 597" on one end and "120 mg" on the other. 180 mg 90’s 500’s 62037-598-90 62037-598-05 Rich yellow/orange opaque capsule imprinted with "Andrx 598" on one end and "180 mg" on the other. 240 mg 90’s 500’s 62037-599-90 62037-599-05 Light brown/orange opaque capsule imprinted with "Andrx 599" on one end and "240 mg" on the other.
300 mg 90’s 500’s 62037-600-90 62037-600-05 Orange/orange opaque capsule imprinted with "Andrx 600" on one end and "300 mg" on the other. NOTE: THE PRODUCT MAY HAVE AN ODOR. Storage Conditions: Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].
Avoid excessive humidity. Dispense in tight, light resistant container as defined in USP. Brands listed are the trademarks of their respective owners.
Manufactured By: Teva Pharmaceuticals Parsippany, NJ 07054 Rev. C 4/2026
📦 Storage and Handling ▾
Storage Conditions: Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Avoid excessive humidity. Dispense in tight, light resistant container as defined in USP. Brands listed are the trademarks of their respective owners. Manufactured By: Teva Pharmaceuticals Parsippany, NJ 07054 Rev. C 4/2026
📋 Description ▾
DESCRIPTION Diltiazem hydrochloride, USP is a calcium ion cellular influx inhibitor (slow channel blocker or calcium antagonist). Chemically, diltiazem hydrochloride is 1,5-Benzothiazepin-4(5 H )-one, 3-(acetyloxy)-5-[2-(dimethylamino) ethyl]-2, 3-dihydro-2-(4-methoxyphenyl)-, monohydrochloride,(+)- cis -. The chemical structure is: Diltiazem hydrochloride, USP is a white to off-white crystalline powder with a bitter taste.
It is soluble in water, methanol, and chloroform. It has a molecular weight of 450.98. Diltiazem hydrochloride, USP is formulated as a once-a-day extended-release capsule containing 120 mg diltiazem hydrochloride (equivalent to 110.3 mg diltiazem), 180 mg diltiazem hydrochloride (equivalent to 165.45 mg diltiazem), 240 mg diltiazem hydrochloride (equivalent to 220.6 mg diltiazem), or 300 mg diltiazem hydrochloride (equivalent to 275.75 mg diltiazem).
In addition, each capsule contains the following inactive ingredients: acetyltributyl citrate, ammonio methacrylate copolymer, black iron oxide, cornstarch, D&C Red No. 28, D&C Yellow No. 10, D&C Yellow No.
10 Aluminum Lake, ethylcellulose, FD&C Blue No. 1 Aluminum Lake, FD&C Blue No. 2 Aluminum Lake, FD&C Red No.
40, FD&C Red No. 40 Aluminum Lake, gelatin, magnesium stearate, methacrylic acid copolymer, propylene glycol, polysorbate 80, sucrose, talc, and titanium dioxide. The 180 mg and 240 mg capsules contain yellow iron oxide.
In addition, the 240 mg capsule also contains red iron oxide. For oral administration. This drug meets USP Drug Release 9.
Diltiazem hydrochloride chemical structure
⚠️ Precautions ▾
PRECAUTIONS General Diltiazem hydrochloride is extensively metabolized by the liver and excreted by the kidneys and in bile. Laboratory parameters of renal and hepatic function should be monitored at regular intervals. In subacute and chronic dog and rat studies designed to produce toxicity, high doses of diltiazem were associated with hepatic damage.
In special subacute hepatic studies, oral doses of 125 mg/kg and higher in rats were associated with histological changes in the liver which were reversible when the drug was discontinued. In dogs, doses of 20 mg/kg were also associated with hepatic changes; however, these changes were reversible with continued dosing. Dermatological events (see ADVERSE REACTIONS ) may be transient and may disappear despite continued use of diltiazem hydrochloride.
However, skin eruptions progressing to erythema multiforme and/or exfoliative dermatitis have also been infrequently reported. Should a dermatologic reaction persist, the drug should be discontinued. 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 extended-release capsules (once-a-day dosage) (see WARNINGS ). Diltiazem is both a substrate and an inhibitor of the Pg-p and cytochrome P450 3A4 enzyme system which may affect exposure to diltiazem and concomitant drugs metabolized by those pathways. Patients with renal and/or hepatic impairment may be particularly at risk of exposure changes.
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, titrate anesthetics and calcium blockers slowly. 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. Beta-blockers: Controlled and uncontrolled domestic studies suggest that concomitant use of diltiazem hydrochloride and beta-blockers is usually well tolerated, but available data are not sufficient to predict the effects of concomitant treatment in patients with left ventricular dysfunction or cardiac conduction abnormalities.
Administration of diltiazem hydrochloride concomitantly with propranolol in five normal volunteers resulted in increased propranolol levels in all subjects and bioavailability of propranolol was increased approximately 50%. In vitro , propranolol appears to be displaced from its binding sites by diltiazem. If combination therapy is initiated or withdrawn in conjunction with propranolol, an adjustment in the propranolol dose may be warranted (see WARNINGS ).
Buspirone: In nine healthy subjects, diltiazem significantly increased the mean buspirone AUC 5.5-fold and C max 4.1-fold compared to placebo. The T 1/2 and T max of buspirone were not significantly affected by diltiazem. Enhanced effects and increased toxicity of buspirone may be possible during concomitant administration with diltiazem.
Subsequent dose adjustments may be necessary during coadministration, and should be based on clinical assessment. Carbamazepine: Concomitant administration of diltiazem with carbamazepine has been reported to result in elevated serum levels of carbamazepine (40% to 72% increase), resulting in toxicity in some cases. Cimetidine: A study in six healthy volunteers has shown… [Excerpted — this section continues on DailyMed.]
🍼 Nursing Mothers ▾
Nursing Mothers Diltiazem is excreted in human milk. One report suggests that concentrations in breast milk may approximate serum levels. If use of diltiazem hydrochloride extended-release capsules (once-a-day dosage) is deemed essential, an alternative method of infant feeding should be instituted.
🧬 Pharmacodynamics ▾
Pharmacokinetics and Metabolism Diltiazem is well absorbed from the gastrointestinal tract and is subject to an extensive first-pass effect, giving an absolute bioavailability (compared to intravenous administration) of about 40%. Diltiazem undergoes extensive metabolism in which only 2% to 4% of the unchanged drug appears in the urine. Drugs which induce or inhibit hepatic microsomal enzymes may alter diltiazem disposition.
Total radioactivity measurement following short IV administration in healthy volunteers suggests the presence of other unidentified metabolites, which attain higher concentrations than those of diltiazem and are more slowly eliminated; half-life of total radioactivity is about 20 hours compared to 2 to 5 hours for diltiazem. In vitro binding studies show diltiazem is 70% to 80% bound to plasma proteins. Competitive in vitro ligand binding studies have also shown diltiazem hydrochloride binding is not altered by therapeutic concentrations of digoxin, hydrochlorothiazide, phenylbutazone, propranolol, salicylic acid, or warfarin.
The plasma elimination half-life following single or multiple drug administration is approximately 3.0 to 4.5 hours. Desacetyl diltiazem is also present in the plasma at levels of 10% to 20% of the parent drug and is 25% to 50% as potent as a coronary vasodilator as diltiazem. Minimum therapeutic plasma diltiazem concentrations appear to be in the range of 50 to 200 ng/mL.
There is a departure from linearity when dose strengths are increased; the half-life is slightly increased with dose. A study that compared patients with normal hepatic function to patients with cirrhosis found an increase in half-life and a 69% increase in bioavailability in the hepatically impaired patients. A single study in nine patients with severely impaired renal function showed no difference in the pharmacokinetic profile of diltiazem compared to patients with normal renal function.
Diltiazem hydrochloride extended-release capsules (once-a-day dosage): When compared to a regimen of CARDIZEM tablets at steady-state, more than 95% of drug is absorbed from the diltiazem hydrochloride extended-release capsules (once-a-day dosage) formulation. A single 360 mg dose of the capsule results in detectable plasma levels within 2 hours and peak plasma levels between 10 and 14 hours; absorption occurs throughout the dosing interval. When diltiazem hydrochloride extended-release capsules (once-a-day dosage) was coadministered with a high fat content breakfast, the extent of diltiazem absorption was not affected.
Dose-dumping does not occur. The apparent elimination half-life after single or multiple dosing is 5 to 8 hours. A departure from linearity similar to that seen with CARDIZEM tablets and CARDIZEM SR capsules is observed.
As the dose of diltiazem hydrochloride extended-release capsules (once-a-day dosage) is increased from a daily dose of 120 mg to 240 mg, there is an increase in the area under the curve (AUC) of 2.7 times. When the dose is increased from 240 mg to 360 mg, there is an increase in the AUC of 1.6 times. In an in vitro dissolution study, the release rate of diltiazem from diltiazem hydrochloride extended-release capsules (once-a-day dosage) increased significantly as the alcohol percentage in the dissolution medium increased.
The effect of alcohol on the release rate may lead to a change in the pharmacokinetics of diltiazem, such as a more rapid absorption and/or an increase in the systemic exposure of diltiazem (see PRECAUTIONS , Drug Interactions ).
📄 Carcinogenesis, Mutagenesis, Impairment of Fertility ▾
Carcinogenesis, Mutagenesis, Impairment of Fertility A 24-month study in rats at oral dosage levels of up to 100 mg/kg/day and a 21-month study in mice at oral dosage levels of up to 30 mg/kg/day showed no evidence of carcinogenicity. There was also no mutagenic response in vitro or in vivo in mammalian cell assays or in vitro in bacteria. No evidence of impaired fertility was observed in a study performed in male and female rats at oral dosages of up to 100 mg/kg/day.
📄 Package Label / Principal Display Panel ▾
PRINCIPAL DISPLAY PANEL - 120mg NDC 62037-597-90 Cartia XT ® (Diltiazem Hydrochloride Extended- Release Capsules, USP) 120 mg ONCE-A-DAY DOSAGE Rx only 90 Capsules 1
PRINCIPAL DISPLAY PANEL - 180mg NDC 62037-598-90 Cartia XT ® (Diltiazem Hydrochloride Extended- Release Capsules, USP) 180 mg ONCE-A-DAY DOSAGE Rx only 90 Capsules 1
PRINCIPAL DISPLAY PANEL - 240mg NDC 62037-599-90 Cartia XT ® (Diltiazem Hydrochloride Extended- Release Capsules, USP) 240 mg ONCE-A-DAY DOSAGE Rx only 90 Capsules 1
PRINCIPAL DISPLAY PANEL - 300mg NDC 62037-600-90 Cartia XT ® (Diltiazem Hydrochloride Extended- Release Capsules, USP) 300 mg ONCE-A-DAY DOSAGE Rx only 90 Capsules 1