Isoproterenol

dr.joan

Isoproterenol :

Trade names: Isuprel

Class: Sympathomimetic

Pregnancy: (Category C)

Action:
§ Isoproterenol is a synthetic catecholamine that stimulates both beta1 and beta2 adrenergic receptors
§ (No alpha receptor capabilities).
§ Inotropic Sympathomimetic ' non selective beta agonist '
§ 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.
Indications
§ Hemodynamically significant bradycardia unresponsive to atropine, TCP, dopamine and epinephrine.
§ Management of torsades de pointes. (it refers to a specific variety of ventricular tachycardia that exhibits distinct characteristics on the electrocardiogram).

Contraindications

§ Hypotension (non-rate related).
§ Cardiac arrest.
§ Ischemic heart disease.

Adverse Reactions

§ Dysrhythmias
§ Hypotension
§ Precipitation of angina
§ Facial flushing

Drug Interactions

§ MAO inhibitors and bretylium potentiate the effects of catecholamine.
§ Beta adrenergic antagonists may blunt Inotropic response.
§ Sympathomimetic and phosphodiesterase inhibitors may exacerbate dysrhythmia response.

Dose:

Adult

Infusion: 2-10 mcg/min titrated to increase HR and perfusion. Typical preparation: dilute 1 mg in 250 ml for a concentration of 4mcg/ml)

Pediatric

Infusion: 0.5 mcg/kg/min titrated to increased HR and perfusion. Typical preparation: dilute 0.6 mg/kg to create 100 ml solution.

Nursing Considerations

§ Isoproterenol increases myocardial oxygen demand, and can induce serious dysrhythmia (including VT and VF). So deal with it with caution and monitor always for adverse effects.
§ Administer via infusion pump to ensure precise flow rates.
§ May exacerbate tachydysrhythmias due to 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.