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Basic Drug Info
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)



Clinical Trials:


Indications and Usage

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.
Paroxysmal supraventricular tachycardia -- An episodic form of supraventricular tachycardia, with abrupt onset and termination.

Lown-Ganong-Levine Syndrome -- A form of ventricular pre-excitation characterized by a short PR interval and a normal QRS complex. In this syndrome, the atrial impulse conducts via the James fibers which connect the atrium to BUNDLE OF HIS bypassing the upper ATRIOVENTRICULAR NODE. HEART VENTRICLES are depolarized normally through the His-Purkinje system.

Atrial Flutter -- Rapid, irregular atrial contractions caused by a block of electrical impulse conduction in the right atrium and a reentrant wave front traveling up the inter-atrial septum and down the right atrial free wall or vice versa. Unlike ATRIAL FIBRILLATION which is caused by abnormal impulse generation, typical atrial flutter is caused by abnormal impulse conduction. As in atrial fibrillation, patients with atrial flutter cannot effectively pump blood into the lower chambers of the heart (HEART VENTRICLES).

Atrial Fibrillation -- Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (HEART ATRIA). In such case, blood cannot be effectively pumped into the lower chambers of the heart (HEART VENTRICLES). It is caused by abnormal impulse generation.

Supraventricular tachycardia -- A generic expression for any tachycardia that originates above the BUNDLE OF HIS.

Cardiac Flutter --

Atrial fibrillation/flutter --

Cardiac Arrest -- Cessation of heart beat or MYOCARDIAL CONTRACTION. If it is treated within a few minutes, heart arrest can be reversed in most cases to normal cardiac rhythm and effective circulation.

Contraindications

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.
Cardiogenic shock -- Shock resulting from diminution of cardiac output in heart disease.

Complete atrioventricular block -- Complete failure of atrial electrical impulse conduction through the AV node to the ventricles.

Sick Sinus Syndrome -- A condition caused by dysfunctions related to the SINOATRIAL NODE including impulse generation (CARDIAC SINUS ARREST) and impulse conduction (SINOATRIAL EXIT BLOCK). It is characterized by persistent BRADYCARDIA, chronic ATRIAL FIBRILLATION, and failure to resume sinus rhythm following CARDIOVERSION. This syndrome can be congenital or acquired, particularly after surgical correction for heart defects.

Congestive heart failure -- complication of heart diseases; defective cardiac filling and/or impaired contraction and emptying, resulting in the heart's inability to pump a sufficient amount of blood to meet the needs of the body tissues or to be able to do so only with an elevated filling pressure.

Supraventricular tachycardia -- A generic expression for any tachycardia that originates above the BUNDLE OF HIS.

Atrial Flutter -- Rapid, irregular atrial contractions caused by a block of electrical impulse conduction in the right atrium and a reentrant wave front traveling up the inter-atrial septum and down the right atrial free wall or vice versa. Unlike ATRIAL FIBRILLATION which is caused by abnormal impulse generation, typical atrial flutter is caused by abnormal impulse conduction. As in atrial fibrillation, patients with atrial flutter cannot effectively pump blood into the lower chambers of the heart (HEART VENTRICLES).

Atrial Fibrillation -- Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (HEART ATRIA). In such case, blood cannot be effectively pumped into the lower chambers of the heart (HEART VENTRICLES). It is caused by abnormal impulse generation.

Lown-Ganong-Levine Syndrome -- A form of ventricular pre-excitation characterized by a short PR interval and a normal QRS complex. In this syndrome, the atrial impulse conducts via the James fibers which connect the atrium to BUNDLE OF HIS bypassing the upper ATRIOVENTRICULAR NODE. HEART VENTRICLES are depolarized normally through the His-Purkinje system.

Tachycardia, Ventricular -- An abnormally rapid ventricular rhythm usually in excess of 150 beats per minute. It is generated within the ventricle below the BUNDLE OF HIS, either as autonomic impulse formation or reentrant impulse conduction. Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide QRS complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (AV dissociation).

Ventricular Fibrillation -- A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). It is one of the major electrocardiographic patterns seen with CARDIAC ARREST.

Hypersensitivity -- Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.

Warnings

VERAPAMIL HYDROCHLORIDE SHOULD BE GIVEN AS A SLOW INTRAVENOUS INJECTION OVER AT LEAST A TWO MINUTE PERIOD OF TIME.

(See DOSAGE AND ADMINISTRATION)

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