|Drug Name:||Verapamil HCl|
|Manufacturer:||AMERICAN REGENT, INC.|
|Other Info:||Gastrointestinal: Nausea (0.9%): abdominal discomfort (0.6%).In rare cases of hypersensitive patients, broncho/laryngeal spasm accompanied by itch and urticaria have been reported.The following reactions have been reported at low frequency: emotional depression, rotary nystagmus, sleepiness, vertigo, muscle fatigue, diaphoresis, and respiratory failure.Suggested Treatment of Acute Cardiovascular Adverse Reactions*The frequency of these adverse reactions was quite low and experience with their treatment has been limited. Adverse ReactionProven Effective TreatmentSupportive Treatment *Actual treatment and dosage should depend on the severity of the clinical situation and the judgement and experience of the treating physician. 1. Symptomatic hypotension requiring treatmentCalcium chloride (IV) Norepinephrine bitartrate (IV) Metaraminol bitartrate (IV) Isoproterenol HCI (IV) Dopamine (IV)Intravenous fluids Trendelenburg position 2. Bradycardia, AV block, AsystoleIsoproterenol HCI (IV) Calcium chloride (IV) Cardiac pacing LevarterenoI bitartrate (IV) Atropine (IV)Intravenous fluids (slow drip) 3. Rapid ventricular rate (due to antegrade conduction in flutter/fibrillation with W-P-W or L-G-L syndromes)DC-cardioversion (high energy may be required) Procainamide (IV) Lidocaine (IV)Intravenous fluids (slow drip)|
Intravenous Verapamil HCI is indicated for the following:Rapid conversion to sinus rhythm of paroxysmal supraventricular tachycardias, including those associated with accessory bypass tracts (Wolff-Parkinson-White [W-P-W] and Lown-Ganong-Levine [L-G-L] syndromes).
When clinically advisable, appropriate vagal maneuvers (e.g., Valsalva maneuver) should be attempted prior to verapamil hydrochloride administration.Temporary control of rapid ventricular rate in atrial flutter or atrial fibrillation except when the atrial flutter and/or atrial fibrillation are associated with accessory bypass tracts (Wolff-Parkinson-White [W-P-W] and Lown-Ganong-Levine [L-G-L] syndromes).In controlled studies in the United States, about 60% of patients with supraventricular tachycardia converted to normal sinus rhythm within 10 minutes after intravenous verapamil.
Uncontrolled studies reported in the world literature describe a conversion rate of about 80%.
About 70% of patients with atrial flutter and/or fibrillation with a fast ventricular rate respond with a decrease in ventricular rate of at least 20%.
Conversion of atrial flutter or fibrillation to sinus rhythm is uncommon (about 10%) after verapamil and may reflect the spontaneous conversion rate, since the conversion rate after placebo was similar.
Slowing of the ventricular rate in patients with atrial fibrillation/flutter lasts 30 to 60 minutes after a single injection.Because a small fraction (<1%) of patients treated with verapamil respond with life-threatening adverse responses (rapid ventricular rate In atrial flutter/fibrillation and an accessory bypass tract, marked hypotension, or extreme bradycardia/asystole - see Contraindications and Warnings), the initial use of intravenous verapamil should, if possible, be in a treatment setting with monitoring and resuscitation facilities, including DC-cardioversion capability (see Suggested Treatment of Acute Cardiovascular Adverse Reactions).As familiarity with the patient's response is gained, use in an office setting may be acceptable.Cardioversion has been used safely and effectively after intravenous verapamil.
Intravenous Verapamil HCI is contraindicated in:Severe hypotension or cardiogenic shock.Second- or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker).Sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker).Severe congestive heart failure (unless secondary to a supraventricular tachycardia amenable to verapamil therapy.)Patients receiving intravenous beta adrenergic blocking drugs (e.g., propranolol).
Intravenous verapamil and intravenous beta adrenergic blocking drugs should not be administered in close proximity to each other (within a few hours), since both may have a depressant effect on myocardial contractility and AV conduction.Patients with atrial flutter or atrial fibrillation and an accessory bypass tract (i.e.
Wolff-Parkinson-White, Lown-Ganong-Levine syndromes) are at risk to develop ventricular tachyarrhythmia including ventricular fibrillation if verapamil is administered.
Therefore, the use of verapamil in these patients is contraindicated.Ventricular Tachycardia.
Administration of intravenous verapamil to patients with wide-complex ventricular-tachycardia (QRS ? 0.12 sec) can result in marked hemodynamic deterioration and ventricular fibrillation.Proper pretherapy diagnosis and differentiation from wide-complex supraventricular tachycardia is imperative in the emergency room setting.Known hypersensitivity to verapamil hydrochloride.
VERAPAMIL HYDROCHLORIDE SHOULD BE GIVEN AS A SLOW INTRAVENOUS INJECTION OVER AT LEAST A TWO MINUTE PERIOD OF TIME.(See DOSAGE AND ADMINISTRATION)