Class
Description
Onset and Duration
Indications
Contraindications
Adverse Reactions
Drug Interactions
How Supplied
Dosage and Administration
Special Considerations
Sympathomimetic
Isoproterenol is a synthetic catecholamine that stimulates both beta1- and beta2-adrenergic receptors (no alpha-receptor capabilities). The drug affects the heart by increasing inotropic and chronotropic activity. In addition, isoproterenol causes arterial and bronchial dilation and is sometimes administered via aerosolization as a bronchodilator to treat bronchial asthma and bronchospasm. (Because of the undesirable beta2 cardiac effects, the use of this drug as a bronchodilator is uncommon in the prehospital setting.)
Hemodynamically stable bradycardias that are resistant to atropine.
Heart blocks with palpable pulse
Management of torsades de pointes
Ventricular tachycardia
Ventricular fibrillation
Hypotension
Pulseless idioventricular rhythm
Ischemic heart disease
Cardiac arrest
Dysrhythmias
Hypotension
Precipitation of angina pectoris
Facial flushing
MAOls and bretylium potentiate the effects of catecholamines.
Beta-adrenergic antagonists mav blunt inotropic response.
Sympathomimetics and phosphodiesterase inhibitors may exacerbate dysrhythmia response.
1 mg in 1-ml or 5-ml ampule and prefilled syringe
Pregnancy safety: Category C.
Isoproterenol increases myocardial oxygen demand and can induce serious dvsrhythmias (including ventricular tachycardia and ventricular fibrillation). May exacerbate tachydysrhythmias because of digitalis toxicity or hypokalemia. Newer inotropic agents have replaced isoproterenol in most clinical settings. If electronic pacing is available, it should be used instead of isoproterenol or as soon as possible after the drug has been initiated.