ISUPREL- isoproterenol hydrochloride injection, solution
Valeant Pharmaceuticals North America LLC
Isoproterenol Hydrochloride Injection, USP
Sterile Injection
Rx only
DESCRIPTION
Isoproterenol hydrochloride is 3,4-Dihydroxy-?-[(isopropylamino)methyl] benzyl alcohol hydrochloride, a synthetic sympathomimetic amine that is structurally related to epinephrine but acts almost exclusively on beta receptors. The molecular formula is C11 H17 NO3 ? HCl. It has a molecular weight of 247.72 and the following structural formula:
Isoproterenol hydrochloride is a racemic compound.
Structural Compound -- Isuprel
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Each milliliter of the sterile solution contains:
Isoproterenol hydrochloride injection, USP 0.2 mg
Edetate Disodium (EDTA) 0.2 mg
Sodium Chloride 7.0 mg
Sodium Citrate, Dihydrate 2.07 mg
Citric Acid, Anhydrous 2.5 mg
Water for Injection 1.0 mL
The pH is adjusted between 3.5 and 4.5 with hydrochloric acid or sodium hydroxide.
The sterile solution is nonpyrogenic and can be administered by the intravenous, intramuscular, subcutaneous or intracardiac routes.
CLINICAL PHARMACOLOGY
Isoproterenol is a potent nonselective beta-adrenergic agonist with very low affinity for alpha-adrenergic receptors. Intravenous infusion of isoproterenol in man lowers peripheral vascular resistance, primarily in skeletal muscle but also in renal and mesenteric vascular beds. Diastolic pressure falls. Renal blood flow is decreased in normotensive subjects but is increased markedly in shock. Systolic blood pressure may remain unchanged or rise, although mean arterial pressure typically falls. Cardiac output is increased because of the positive inotropic and chronotropic effects of the drug in the face of diminished peripheral vascular resistance. The cardiac effects of isoproterenol may lead to palpitations, sinus tachycardia, and more serious arrhythmias; large doses of isoproterenol may cause myocardial necrosis in animals.
Isoproterenol relaxes almost all varieties of smooth muscle when the tone is high, but this action is most pronounced on bronchial and gastrointestinal smooth muscle. It prevents or relieves bronchoconstriction, but tolerance to this effect develops with overuse of the drug.
In man, isoproterenol causes less hyperglycemia than does epinephrine. Isoproterenol and epinephrine are equally effective in stimulating the release of free fatty acids and energy production.
Absorption, Fate, and Excretion. Isoproterenol is metabolized primarily in the liver and other tissues by COMT. Isoproterenol is a relatively poor substrate for MAO and is not taken up by sympathetic neurons to the same extent as are epinephrine and norepinephrine. The duration of action of isoproterenol may therefore be longer than that of epinephrine, but is still brief.
INDICATIONS AND USAGE
Isoproterenol hydrochloride injection is indicated:
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For mild or transient episodes of heart block that do not require electric shock or pacemaker therapy.
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For serious episodes of heart block and Adams-Stokes attacks (except when caused by ventricular tachycardia or fibrillation). (See CONTRAINDICATIONS.)
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For use in cardiac arrest until electric shock or pacemaker therapy, the treatments of choice, is available. (See CONTRAINDICATIONS.)
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For bronchospasm occurring during anesthesia.
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As an adjunct to fluid and electrolyte replacement therapy and the use of other drugs and procedures in the treatment of hypovolemic and septic shock, low cardiac output (hypoperfusion) states, congestive heart failure, and cardiogenic shock. (See WARNINGS.)
