Isoproterenol Hydrochloride and Lidocaine Hydrochloride

• Generic Name: isoproterenol
• Dosage Forms: n.a.
• Other Brand Names: Isuprel

Used for treatment of heart block and Adams-Stokes attacks. Also has been used for treatment of ventricular arrhythmias secondary to AV nodal block and carotid sinus hypersensitivity. However, evidence supporting benefit in patients with cardiac arrhythmias generally lacking; safer and more effective alternatives such as cardiac pacing and other drug therapies are available.

Has been used in the treatment of cardiac arrest until defibrillation or emergency pacemaker therapy could be employed. However, experts state that isoproterenol is not a drug of choice in ACLS and should only be considered in this setting for treatment of symptomatic bradycardia unresponsive to atropine or as a temporary measure until pacemaker therapy can be instituted. Should not be used for resuscitation in patients with cardiac arrest or hypotension because of potential deleterious effects (e.g., exacerbation of ischemia, arrhythmias, peripheral vasodilation).

Must not be administered to patients with acetylcholinesterase-induced bradycardias; however, may be beneficial at high doses in refractory bradycardia caused by β-adrenergic blocking agents.

Used as adjunctive therapy to produce cardiac stimulation and vasodilation in the treatment of shock.

The value of isoproterenol therapy in shock has been questioned because the drug increases oxygen demand in the myocardium and other tissues to levels that may not be met by increased blood flow. Efficacy in reducing mortality in refractory shock not demonstrated.

Vasopressors such as norepinephrine and epinephrine generally considered drugs of choice for effective hemodynamic management of shock.

Isoproterenol generally not recommended for cardiogenic shock; increases in myocardial oxygen consumption and cardiac workload usually outweigh benefits, and arrhythmias can occur more readily.

Should not be used in patients with drug-induced distributive shock; may worsen hypotension by further decreasing systemic vascular resistance.

IV isoproterenol may be useful in bronchospasm occurring during anesthesia but must be administered with extreme caution, if at all, in patients receiving cyclopropane or halogenated hydrocarbon general anesthetics.

Has been used as a bronchodilator in the symptomatic treatment of bronchial asthma and reversible bronchospasm that may occur in association with chronic bronchitis, pulmonary emphysema, bronchiectasis, and other chronic obstructive pulmonary disorders. However, oral, sublingual, and oral inhalation preparations of the drug no longer are commercially available in the US.

Has been used by IV infusion to reverse decreases in cardiac output and circulating pulmonary blood volume and to reverse increases in pulmonary arterial pressure and pulmonary vascular resistance occurring during pulmonary embolism.

Has been used as an aid in the diagnosis of CAD. Also has been used in the diagnosis of CAD by increasing myocardial oxygen consumption and intensifying symptoms of ischemia.

Has been used as an aid in diagnosing the etiology of mitral regurgitation.

• Generic Name: lidocaine
• Dosage Forms: n.a.
• Other Brand Names: UAD Caine, Xylocaine HCl, Xylocaine-MPF, Lidoject 1, Xylocaine Dental Cartridges, Lidoject 2, Xylocaine Duo-Trach Kit, Xylocaine HCl For Spinal, L-Caine, Dilocaine, Nervocaine, Truxacaine, Anestacaine

Alternative to other antiarrhythmic drugs (e.g., amiodarone, procainamide, sotalol) for the acute treatment of life-threatening ventricular arrhythmias such as those that occur following MI or during cardiac manipulative procedures such as cardiac surgery.

Used during cardiac arrest for treatment of refractory (i.e., resistant to CPR, defibrillation, and a vasopressor [epinephrine]) VF or pulseless VT. Considered an alternative to amiodarone for this use in current ACLS guidelines in adults; in pediatric patients, current evidence supports use of either amiodarone or lidocaine.

Alternative to other antiarrhythmic agents or synchronized electrical cardioversion in the treatment of hemodynamically stable monomorphic VT; however, other agents (e.g., procainamide, sotalol, amiodarone) preferred.

Treatment of status epilepticus, as a last resort.