|Drug Name:||Diltiazem Hydrochloride|
|Manufacturer:||Baxter Healthcare Corporation|
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 hydrochloride. These antiarrhythmic agents were intravenous or oral digoxin, Class 1 antiarrthythmics (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.
Diltiazem hydrochloride injection is contraindicated in:Patients with sick sinus syndrome except in the presence of a functioning ventricular pacemaker.Patients with second- or third-degree AV block except in the presence of a functioning ventricular pacemaker.Patients with severe hypotension or cardiogenic shock.Patients who have demonstrated hypersensitivity to the drug.Intravenous diltiazem and intravenous beta-blockers should not be administered together or in close proximity (within a few hours).Patients with atrial fibrillation or atrial flutter associated with an accessory bypass tract such as in WPW syndrome or short PR syndrome.
As with other agents which slow AV nodal conduction and do not prolong the refractoriness of the accessory pathway (e.g., verapamil, digoxin), in rare instances patients in atrial fibrillation or atrial flutter associated with an accessory bypass tract may experience a potentially life-threatening increase in heart rate accompanied by hypotension when treated with diltiazem hydrochloride injection.
As such, the initial use of diltiazem hydrochloride injection should be, if possible, in a setting where monitoring and resuscitation capabilities, including DC cardioversion/defibrillation, are present (see OVERDOSAGE).
Once familiarity of the patient’s response is established, use in an office setting may be acceptable.Patients with ventricular tachycardia.
Administration of other calcium channel blockers to patients with wide complex tachycardia (QRS ?0.12 seconds) has resulted in hemodynamic deterioration and ventricular fibrillation.It is important that an accurate pretreatment diagnosis distinguish wide complex QRS tachycardia of superventricular origin from that of ventricular origin prior to administration of diltiazem hydrochloride injection.
Diltiazem prolongs AV nodal conduction and refractoriness that may rarely result in second- or third-degree AV block in sinus rhythm. Concomitant use of diltiazem with agents known to affect cardiac conduction may result in additive effects (see PRECAUTIONS, Drug Interactions).If high-degree AV block occurs in sinus rhythm, intravenous diltiazem should be discontinued and appropriate supportive measures instituted (seeOVERDOSAGE).