Used in the management of Prinzmetal variant angina and chronic stable angina pectoris.
Calcium channel blockers considered the drugs of choice in management of Prinzmetal variant angina.
Appears to be as effective as β-adrenergic blocking agents (e.g., propranolol) and/or oral nitrates in the management of chronic stable angina pectoris; however, generally should be used only when the patient cannot tolerate adequate doses of or is refractory to these drugs.
Management of unstable angina† in patients who have continuing or ongoing ischemia when therapy with β-blocking agents and nitrates is inadequate, not tolerated, or contraindicated and when severe left ventricular dysfunction, pulmonary edema, or other contraindications are not present.
Hypertension
Management of hypertension (alone or in combination with other classes of antihypertensive agents).
Only extended-release formulations currently are recommended for management of hypertension.
One of several preferred initial therapies for hypertensive patients with a high risk of developing coronary artery disease, including those with diabetes mellitus.
Can be used as monotherapy for initial management of uncomplicated hypertension; however, thiazide diuretics are preferred for monotherapy by JNC 7.
Supraventricular Tachyarrhythmias
Management of supraventricular tachyarrhythmias, including rapid conversion to sinus rhythm of paroxysmal supraventricular tachycardias (PSVT) (e.g., those associated with Wolff-Parkinson-White or Lown-Ganong-Levine syndrome) and temporary control of rapid ventricular rate in atrial flutter or fibrillation.
One of several preferred antiarrhythmic agents for the treatment of stable, narrow-complex supraventricular tachycardias (e.g., paroxysmal supraventricular tachycardia [reentry supraventricular tachycardia], ectopic or multifocal atrial tachycardia†, junctional tachycardia†) if the rhythm is not controlled by vagal maneuvers or adenosine and to control the ventricular response rate in atrial fibrillation or flutter.
AMI
Calcium-channel blocking agents have not proved beneficial in the early treatment or secondary prevention of AMI† and the possibility that they may be harmful has been raised.
May be used for relief of ongoing ischemia or to control rapid ventricular response with atrial fibrillation after an AMI† when β-adrenergic blocking agents are ineffective or contraindicated, but only in patients in whom there is no evidence of CHF, left-ventricular dysfunction, or AV block and only after weighing carefully the potential benefits versus risks, particularly negative inotropic effects and concerns about short-acting formulations of the drugs.
Hyperthyroidism
Short-term adjunctive therapy in the treatment of tachycardia and tachyarrhythmias in patients with hyperthyroidism† and/or thyrotoxicosis† in whom therapy with β-adrenergic blocking agents is contraindicated or not tolerated.
Dosage and Administration
Administration
Administer by direct IV injection, continuous IV infusion, or orally.
Oral Administration
Conventional Tablets
Administer tablets orally 3–4 times daily before meals and at bedtime.
Extended-release Capsules
Administer orally; directions for administration (e.g., frequency, whether to administer with or without food, potential for opening capsules and mixing with food) may vary by manufacturer and formulation; consult specific manufacturer's information for additional information.
Cardizem® CD, Dilacor XR®, Dilt-XR®, Tiazac®, Taztia XT®, Cartia XT®, or Diltia XT® may be administered once daily; diltiazem hydrochloride extended-release capsules (12 hours) are administered twice daily.
Cardizem® CD and Cartia XT® may be administered without regard to meals. However, Dilacor XR®, Diltia XT®, and Dilt-XR® should be taken on an empty stomach, swallowed whole and not opened, chewed, or crushed.
Tiazac® and Taztia XT® may be opened and the entire contents sprinkled on a small amount of applesauce (not hot) immediately prior to administration; subdividing the contents of capsules is not recommended. Swallow the entire mixture without chewing. Immediately drink a glass of cool water to ensure that all of the mixture is swallowed. Do not store the sprinkle/food mixture for use at a later time.
Extended-release Tablets
Administer orally once daily without regard to meals. Tablet should be swallowed whole and not chewed or crushed.
IV Injection
Monitor ECG and BP continuously during IV administration.
Reconstitution
Prepare solutions from the powder for injection (Lyo-Ject®) according to the manufacturer's directions.
Dilution
Injection solutions containing 5 mg/mL or powder for injection that has been reconstituted according to manufacturer's directions may be administered by direct IV injection without any further dilution.
Rate of Administration
Administer over 2 minutes.
IV Infusion
Reconstitution
Prepare solutions from the powder for injection (Lyo-Ject®) according to the manufacturer's directions.
Dilution
Dilute 5 mg/mL injection solution or reconstituted powder for injection in the appropriate volume of a compatible infusion solution (i.e., 0.9% sodium chloride, 5% dextrose, or 5% dextrose and 0.45% sodium chloride) to produce a final diltiazem hydrochloride concentration of 1, 0.83, or 0.45 mg/mL, respectively.
Dilution of Commercially Available Injection or Reconstituted Lyo-Ject® 5 mg/mL solution.
Quantity of 5 mg/mL Solution
Diluent Volume
Final Concentration
25 mL
100 mL
1 mg/mL
50 mL
250 mL
0.83 mg/mL
50 mL
500 mL
0.45 mg/mL
Rate of Administration
Usually 10 mg/hour; however, may range from 5–15 mg/hour.
Dosage
Available as diltiazem hydrochloride; dosage expressed in terms of the salt.
Adults
Prinzmetal Variant Angina
Conventional Tablets
Oral
Initially, 30 mg 4 times daily. Increase gradually at 1- to 2-day intervals until optimum control is obtained. Usual maintenance dosage is 180–360 mg daily. After manifestations are controlled, reduce dosage to lowest level that will maintain relief of symptoms.
Extended-release Capsules
Oral
Initially, 120 or 180 mg once daily when administered as extended-release capsules (Cardizem® CD, Cartia XT®). Individualize dosage based on response; titrate dosage increases over 7–14 days. Some patients may respond to higher dosages of up to 480 mg once daily.
Chronic Stable Angina
Conventional Tablets
Oral
Initially, 30 mg 4 times daily. Increase gradually at 1- to 2-day intervals until optimum control is obtained. Usual maintenance dosage is 180–360 mg daily. After manifestations are controlled, reduce dosage to lowest level that will maintain relief of symptoms.
Extended-release Capsules
Oral
Initially, 120 (Dilacor XR®, Diltia XT®, Dilt-XR®) or 120–180 mg (Cardizem® CD, Cartia XT®, Tiazac®, Taztia XT®) once daily when administered as extended-release capsules. Individualize dosage based on response; titrate dosage increases over 7–14 days. Some patients may respond to higher dosages of up to 480 (Cardizem® CD, Cartia XT®, Dilacor XR®, Diltia XT®, Dilt-XR®) to 540 mg (Tiazac®, Taztia XT®) once daily.
Extended-release Tablets
Oral
Initially, 180 mg once daily when administered as extended-release tablets (Cardizem® LA). Individualize dosage based on response; titrate dosage increases over 7–14 days. Some patients may respond to higher dosages of up to 360 mg once daily.
Hypertension
Extended-release Capsules
Oral
Maximum hypotensive effect associated with a given dosage level usually is observed within 14 days.
Recommended Dosages for Management of Hypertension
JNC 7 recommends a usual maximum dosage of 420 mg daily for these preparations.
Switching to Cardizem® CD Extended-release Capsules
Oral
Patients whose BP is adequately controlled with diltiazem therapy (as tablets or other extended-release capsules) alone or in combination with another antihypertensive agent may be safely switched to Cardizem® CD or Cartia XT® extended-release capsules or Cardizem® LA extended-release tablets at the nearest equivalent daily dosage. Subsequent titration of dosage is based on the clinical response of the patient.
Conventional Tablets
Oral
Initially, 30 mg 3 times daily; may be increased to a maximum dosage of 360 mg daily given in 3 or 4 divided doses.†
Extended-release Tablets
Oral
Initially, 180–240 mg daily; however, some patients may respond to a lower dosage. Individualize dosage based on response; maximum hypotensive effect associated with a given dosage level usually is observed within 14 days. Usual maintenance dosage is 120–540 mg daily; however, JNC 7 recommends a usual maximum dosage of 420 mg daily.
Initially, 15–20 mg (or 0.25 mg/kg) by direct IV injection over 2 minutes. If response is inadequate (i.e., conversion to normal sinus rhythm does not occur) give a second dose of 20–25 mg (or 0.35 mg/kg) 15 minutes after the initial dose.†
Maintenance infusion: 5–15 mg/hour; titrate dose to heart rate.†
Patients with low body weights should be dosed on a mg/kg basis.†
Ventricular Rate Control in Atrial Fibrillation and Flutter
IV
Initially, 15–20 mg (or 0.25 mg/kg) by direct IV injection over 2 minutes. If response is inadequate, give 20–25 mg (or 0.35 mg/kg) 15 minutes after the initial dose.
Maintenance infusion: 5–15 mg/hour; titrate dose to heart rate.
Prescribing Limits
Adults
Angina
Oral
Cardizem® LA extended-release tablets: Maximum 360 mg daily.
Cardizem® CD, Dilacor XR®, Diltia XT®, Dilt-XR®, and Cartia XT® extended-release capsules: Maximum 480 mg daily.
Tiazac® and Taztia XT® extended-release capsules: Maximum 540 mg daily.
Hypertension
Oral
Cardizem® conventional tablets†: Maximum 360 mg daily.
Cardizem® CD and Cartia XT® extended release capsules: Maximum 480 mg daily.
Dilt-XR®, Dilacor XR®, Diltia XT®, Taztia XT®, and Tiazac® extended-release capsules and Cardizem® LA extended-release tablets: maximum 540 mg daily.
However, JNC 7 recommends a usual maximum dosage of 420 mg daily for these preparations.
Supraventricular Tachyarrhythmias
IV
Maintenance infusion: Maximum 15 mg/hour for ≤24 hours.
Special Populations
Hepatic Impairment
Supraventricular Tachyarrhythmias
Atrial Fibrillation and Flutter
IV
Maintenance infusion: Dosage requirements may be lower.
Geriatric Patients
Angina
Select dosage cautiously; geriatric patients may respond to lower dosages.
Hypertension
Select dosage cautiously. The manufacturers of Dilacor XR®, Dilt-XR®, and Diltia XT® state that patients 60 years of age or older may respond to an initial daily dosage of 120 mg.
Atrial Fibrillation and Flutter
Maintenance IV infusion: Dosage requirements may be lower.
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