DOSAGE AND ADMINISTRATION
Direct Intravenous Single Injections (Bolus)
The initial dose of diltiazem hydrochloride injection should be 0.25 mg/kg actual body weight as a bolus administered over 2 minutes (20 mg is a reasonable dose for the average patient). If response is inadequate, a second dose may be administered after 15 minutes. The second bolus dose of diltiazem hydrochloride injection should be 0.35 mg/kg actual body weight administered over 2 minutes (25 mg is a reasonable dose for the average patient). Subsequent intravenous bolus doses should be individualized for each 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.
Continuous Intravenous Infusion
For continued reduction of the heart rate (up to 24 hours) in patients with atrial fibrillation or atrial flutter, an intravenous infusion of diltiazem hydrochloride injection or diltiazem hydrochloride for injection may be administered. (For reconstitution of diltiazem hydrochloride for injection, see instructions contained within packaging.) Immediately following bolus administration of 20 mg (0.25 mg/kg) or 25 mg (0.35 mg/kg) diltiazem hydrochloride injection and reduction of heart rate, begin an intravenous infusion of diltiazem hydrochloride injection or diltiazem hydrochloride for injection. The recommended initial infusion rate of diltiazem hydrochloride injection or diltiazem hydrochloride for injection is 10 mg/h. Some patients may maintain response to an initial rate of 5 mg/h. The infusion rate may be increased in 5 mg/h increments up to 15 mg/h as needed, if further reduction in heart rate is required. The infusion may be maintained for up to 24 hours.
Diltiazem shows dose-dependent, non-linear pharmacokinetics. Duration of infusion longer than 24 hours and infusion rates greater than 15 mg/h have not been studied. Therefore, infusion duration exceeding 24 hours and infusion rates exceeding 15 mg/h are not recommended.
Dilution
To prepare diltiazem hydrochloride injection for continuous intravenous infusion, aseptically transfer the appropriate quantity (see chart) of diltiazem hydrochloride to the desired volume of either Normal Saline, D5W, or D5W/0.45% NaCl. Mix thoroughly. Keep diluted diltiazem hydrochloride injection refrigerated until use. Use within 24 hours.
To prepare diltiazem hydrochloride for injection for continuous intravenous infusion, assemble the ADD-Vantage vial as directed for use with either 0.9% Sodium Chloride or Dextrose (5%) injection. Mix thoroughly. Keep diluted diltiazem hydrochloride for injection at controlled room temperature 15° to 30°C (59° to 86°F) [See USP] or refrigerated 2° to 8°C (36° to 46°F) until use. Use within 24 hours.
| Diluent Volume | Quantity of Diltiazem hydrochloride injection | Final Concentration | Administration | |
|---|---|---|---|---|
| Dose* | Infusion Rate | |||
| ||||
| 100 mL | 125 mg (25 mL) Final Volume 125 mL | 1 mg/mL | 10 mg/h 15 mg/h | 10 mL/h 15 mL/h |
| 250 mL | 250 mg (50 mL) Final Volume 300 mL | 0.83 mg/mL | 10 mg/h 15 mg/h | 12 mL/h 18 mL/h |
| 500 mL | 250 mg (50 mL) Final Volume 550 mL | 0.45 mg/mL | 10 mg/h 15 mg/h | 22 mL/h 33 mL/h |
| Diluent Volume | Quantity of Diltiazem hydrochloride injection | Final Concentration | Administration | |
|---|---|---|---|---|
| Dose* | Infusion Rate | |||
| ||||
| 100 mL | 100 mg (1 ADD-Vantage vial) | 1 mg/mL | 10 mg/h 15 mg/h | 10 mL/h 15 mL/h |