What is the oral dose of Diltiazem (Calcium Channel Blocker)?

From the Guidelines

The oral dose of diltiazem for adults typically ranges from 180-420 mg daily for extended-release formulations, taken once daily, as indicated in the seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure 1.

Diltiazem Dosing Considerations

When considering the use of diltiazem, it's essential to note the different formulations and their respective dosing ranges.

• The extended-release formulations, such as Cardizem CD, Dilacor XR, and Tiazac, are usually taken once daily, with a dose range of 180-420 mg 1.
• Another extended-release formulation, Cardizem LA, has a dose range of 120-540 mg, also taken once daily 1.

Clinical Use and Considerations

Diltiazem is used in the management of hypertension and angina. Its mechanism of action involves blocking calcium channels in the heart and blood vessels, which leads to reduced heart rate, slowed electrical conduction in the heart, and relaxation of blood vessels.

• This results in decreased blood pressure and reduced oxygen demand by the heart, making it effective for both hypertension and angina.
• Patients should be advised to take extended-release formulations whole, without crushing or chewing them, and to be consistent with the timing of their dose relative to meals for optimal absorption.

Special Populations

Elderly patients or those with liver or kidney impairment may require lower initial doses and should be monitored closely for adverse effects.

• The dosing may need to be adjusted based on the patient's response to treatment and the presence of any side effects.
• As with any medication, it's crucial to weigh the benefits of diltiazem against potential risks and to consider alternative treatments if necessary.

From the FDA Drug Label

Diltiazem Hydrochloride Tablets: Diltiazem is absorbed from the tablet formulation to about 98% of a reference solution Single oral doses of 30 to 120 mg of diltiazem hydrochloride tablets result in detectable plasma levels within 30 to 60 minutes and peak plasma levels 2 to 4 hours after drug administration. As the dose of diltiazem hydrochloride tablets is increased from a daily dose of 120 mg (30 mg qid) to 240 mg (60 mg qid) daily, there is an increase in area-under-the-curve of 2. 3 times. When the dose is increased from 240 mg to 360 mg daily, there is an increase in area-under-the-curve of 1.8 times. The recommended oral dose of diltiazem is between 30 mg and 360 mg daily, given in divided doses of 30 mg to 60 mg every 6 to 8 hours, as indicated by the following dose ranges:

• 120 mg (30 mg qid) to 240 mg (60 mg qid) daily
• Up to 360 mg daily 2

From the Research

Diltiazem Oral Dose

The oral dose of diltiazem is not explicitly stated in the provided studies, but its usage and efficacy in various conditions are discussed.

• Diltiazem is used to treat stable angina, angina due to coronary artery spasm, unstable angina, hypertension, and supraventricular tachyarrhythmias 3.
• Sustained-release diltiazem (D-SR) is given twice a day, with doses of 120 to 180 mg, to treat essential hypertension and angina pectoris 4.
• Calcium-channel blockers, including diltiazem, are useful in the treatment of patients with coexisting systemic hypertension and coronary artery disease 5.
• Diltiazem is among the most widely prescribed agents for the management of essential hypertension, and it reduces the cardiovascular morbidity and mortality associated with uncontrolled hypertension 6.

Therapeutic Effects

The therapeutic effects of diltiazem include:

• Increasing myocardial oxygen supply and decreasing myocardial oxygen demand 3
• Coronary artery dilatation and haemodynamic alterations 3
• Systemic vasodilation, which helps in the treatment of hypertension 5
• Reduction in resting and submaximal exercise heart rate, which improves treadmill capacity and reduces the frequency of angina in patients with stable effort angina 4

Usage and Efficacy

Diltiazem is effective in:

• Treating stable angina and angina due to coronary artery spasm, with efficacy similar to that of nifedipine or verapamil 3
• Treating essential hypertension, especially in patients with low-renin hypertension, such as the elderly and black populations 4
• Managing patients with concomitant coronary artery disease and systemic hypertension 5