Hypertensive or anginal patients who are treated with other formulations of diltiazem can safely be switched to diltiazem hydrochloride extended-release capsules (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 diltiazem hydrochloride extended-release capsules (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 diltiazem hydrochloride extended-release capsules 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 diltiazem hydrochloride extended-release capsules 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.
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
Sublingual nitroglycerin may be taken as required to abort acute anginal attacks during diltiazem therapy.
Prophylactic Nitrate Therapy
Diltiazem hydrochloride extended-release capsules (once-a-day dosage) may be safely coadministered with short- and long-acting nitrates.
Beta-Blockers
(See WARNINGS and PRECAUTIONS.)
Antihypertensives
Diltiazem 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.