Diltiazem (Diltiazem Hydrochloride) - Indications and Dosage

INDICATIONS AND USAGE

NOTE: This drug product is not for direct bolus injection. Text referring to direct bolus injection is provided for information purposes only. Diltiazem Hydrochloride for Injection is indicated for the following:

1. Atrial Fibrillation or Atrial Flutter. Temporary control of rapid ventricular rate in atrial fibrillation or atrial flutter. It should not be used in patients with atrial fibrillation or atrial flutter associated with an accessory bypass tract such as in Wolff- Parkinson-White (WPW) syndrome or short PR syndrome.

2. Paroxysmal Supraventricular Tachycardia. Rapid conversion of paroxysmal supraventricular tachycardias (PSVT) to sinus rhythm. This includes AV nodal reentrant tachycardias and reciprocating tachycardias associated with an extranodal accessory pathway such as the WPW syndrome or short PR syndrome. Unless otherwise contraindicated, appropriate vagal maneuvers should be attempted prior to administration of diltiazem hydrochloride injection.

The use of diltiazem hydrochloride should be undertaken with caution when the patient is compromised hemodynamically or is taking other drugs that decrease any or all of the following: peripheral resistance, myocardial filling, myocardial contractility, or electrical impulse propagation in the myocardium.

For either indication and particularly when employing continuous intravenous infusion, the setting should include continuous monitoring of the ECG and frequent measurement of blood pressure. A defibrillator and emergency equipment should be readily available.

In domestic controlled trials in patients with atrial fibrillation or atrial flutter, bolus administration of diltiazem hydrochloride injection was effective in reducing heart rate by at least 20% in 95% of patients. Diltiazem hydrochloride injection rarely converts atrial fibrillation or atrial flutter to normal sinus rhythm. Following administration of one or two intravenous bolus doses of diltiazem hydrochloride injection, response usually occurs within 3 minutes and maximal heart rate reduction generally occurs in 2 to 7 minutes. Heart rate reduction may last from 1 to 3 hours. If hypotension occurs, it is generally short-lived, but may last from 1 to 3 hours.

A 24-hour continuous infusion of diltiazem injection in the treatment of atrial fibrillation or atrial flutter maintained at least a 20% heart rate reduction during the infusion in 83% of patients. Upon discontinuation of infusion, heart rate reduction may last from 0.5 hours to more than 10 hours (median duration 7 hours). Hypotension, if it occurs, may be similarly persistent.

In the controlled clinical trials, 3.2% of patients required some form of intervention (typically, use of intravenous fluids or the Trendelenburg position) for blood pressure support following diltiazem hydrochloride injection.

In domestic controlled trials, bolus administration of diltiazem hydrochloride injection was effective in converting PSVT to normal sinus rhythm in 88% of patients within 3 minutes of the first or second bolus dose.

Symptoms associated with the arrhythmia were improved in conjunction with decreased heart rate or conversion to normal sinus rhythm following administration of diltiazem hydrochloride injection.

DOSAGE AND ADMINISTRATION

NOTE: This drug product is not for direct bolus injection. Text referring to direct bolus injection is provided for information purposes only.

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 may be administered. 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. The recommended initial infusion rate of diltiazem hydrochloride 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 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 to Add	Final Concentration	Administration
			Dose*	Infusion Rate
100 mL	100 mg (1 ADD-Vantage® Vial)	1 mg/mL	10 mg/h	10 mL/h
			15 mg/h	15 mL/h

*5 mg/h may be appropriate for some patients.

INSTRUCTIONS FOR USE

To Use Vial in ADD-Vantage ^® Flexible Diluent Container

To Open:

Peel overwrap at corner and remove solution container. Some opacity of the plastic due to moisture absorption during the sterilization process may be observed. This is normal and does not affect the solution quality or safety. The opacity will diminish gradually.

To Assemble Vial and Flexible Diluent Container:

(Use Aseptic Technique)

1. Remove the protective covers from the top of the vial and the vial port on the diluent container as follows:

   a. To remove the breakaway vial cap, swing the pull ring over the top of the vial and pull down far enough to start the opening (SEE FIGURE 1.), then pull straight up to remove the cap. (SEE FIGURE 2.) NOTE: Do not access vial with syringe.

   Fig. 1	Fig. 2

   b. To remove the vial port cover, grasp the tab on the pull ring, pull up to break the tie membrane, then pull back to remove the cover. (SEE FIGURE 3.)

2. Screw the vial into the vial port until it will go no further. THE VIAL MUST BE SCREWED IN TIGHTLY TO ASSURE A SEAL. This occurs approximately 1/2 turn (180°) after the first audible click. (SEE FIGURE 4.) The clicking sound does not assure a seal; the vial must be turned as far as it will go.

   NOTE: Once vial is seated, do not attempt to remove. (SEE FIGURE 4.)

3. Recheck the vial to assure that it is tight by trying to turn it further in the direction of assembly.

4. Label appropriately.

   Fig. 3	Fig. 4

To Reconstitute the Drug:

1. Squeeze the bottom of the diluent container gently to inflate the portion of the container surrounding the end of the drug vial.

2. With the other hand, push the drug vial down into the container telescoping the walls of the container. Grasp the inner cap of the vial through the walls of the container. (SEE FIGURE 5.)

3. Pull the inner cap from the drug vial. (SEE FIGURE 6.) Verify that the rubber stopper has been pulled out, allowing the drug and diluent to mix.

4. Mix container contents thoroughly and use within the specified time.

   Fig. 5	Fig. 6

Preparation for Administration:

(Use Aseptic Technique)

1. Confirm the activation and admixture of vial contents.

2. Check for leaks by squeezing container firmly. If leaks are found, discard unit as sterility may be impaired.

3. Close flow control clamp of administration set.

4. Remove cover from outlet port at bottom of container.

5. Insert piercing pin of administration set into port with a twisting motion until the pin is firmly seated. NOTE: See full directions on administration set carton.

6. Lift the free end of the hanger loop on the bottom of the vial, breaking the two tie strings. Bend the loop outward to lock it in the upright position, then suspend container from hanger.

7. Squeeze and release drip chamber to establish proper fluid level in chamber.

8. Open flow control clamp and clear air from set. Close clamp.

9. Attach set to venipuncture device. If device is not indwelling, prime and make venipuncture.

10. Regulate rate of administration with flow control clamp.

WARNING: Do not use flexible containers in series connections.

Compatibility:

Diltiazem Hydrochloride Injection was tested for compatibility with three commonly used intravenous fluids at a maximal concentration of 1 mg diltiazem hydrochloride per milliliter. Diltiazem Hydrochloride Injection was found to be physically compatible and chemically stable in the following parenteral solutions for at least 24 hours when stored in polyvinylchloride (PVC) bags at controlled room temperature 20 to 25°C (68 to 77°F) [see USP] or under refrigeration 2 to 8°C (36 to 46°F).

* dextrose (5%) injection, USP

* sodium chloride (0.9%) injection, USP

* dextrose (5%) and sodium chloride (0.45%) injection, USP

Physical incompatibilities:

Because of potential physical incompatibilities, it is recommended that diltiazem hydrochloride not be mixed with any other drugs in the same container. If possible, it is recommended that diltiazem hydrochloride not be coinfused in the same intravenous line. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.

Diltiazem hydrochloride. Physical incompatibilities (precipitate formation or cloudiness) were observed when diltiazem hydrochloride was infused in the same intravenous line with the following drugs: acetazolamide, acyclovir, aminophylline, ampicillin, ampicillin sodium/sulbactam sodium, cefamandole, cefoperazone, diazepam, furosemide, hydrocortisone sodium succinate, insulin, (regular: 100 units/mL), methylprednisolone sodium succinate, mezlocillin, nafcillin, phenytoin, rifampin, and sodium bicarbonate.

NOTE: Diltiazem Hydrochloride for Injection at a concentration of 1 mg/mL diluted in normal saline was infused in the same intravenous line and was found to be compatible with the following drugs: aminophylline, ampicillin sodium, ampicillin sodium/sulbactam sodium, cefamandole, hydrocortisone sodium succinate, regular insulin (100 units/mL), methylprednisolone sodium succinate, mezlocillin sodium, nafcillin sodium and sodium bicarbonate.

Transition to Further Antiarrhythmic Therapy:

Transition to other antiarrhythmic agents following administration of diltiazem hydrochloride injection is generally safe. However, reference should be made to the respective agent manufacturer’s package insert for information relative to dosage and administration.

In controlled clinical trials, therapy with antiarrhythmic agents to maintain reduced heart rate in atrial fibrillation or atrial flutter or for prophylaxis of PSVT was generally started within 3 hours after bolus administration of diltiazem. These antiarrhythmic agents were intravenous or oral digoxin, Class 1 antiarrhythmics (e.g., quinidine, procainamide), calcium channel blockers, and oral beta-blockers.

Experience in the use of antiarrhythmic agents following maintenance infusion of diltiazem hydrochloride injection is limited. Patients should be dosed on an individual basis and reference should be made to the respective manufacturer’s package insert for information relative to dosage and administration.

HOW SUPPLIED

Diltiazem Hydrochloride for Injection is supplied in single-dose containers as follows:

List No.	Container	Size
4350	10 ADD-Vantage® Vials/Tray	100 mg

PRODUCT IS TO BE STORED AT 20 TO 25°C (68 TO 77°F). [SEE USP CONTROLLED ROOM TEMPERATURE.] DO NOT FREEZE. RECONSTITUTED MATERIAL IS STABLE FOR 24 HOURS AT CONTROLLED ROOM TEMPERATURE OR REFRIGERATED 2 to 8°C (36 to 46°F). SINGLE-USE VIAL.

Rev: June, 2006

©Hospira 2006 EN-1222 Printed in USA

HOSPIRA, INC., LAKE FOREST, IL 60045 USA