Isoproterenol

Isoproterenol hydrochloride injection is indicated: To improve hemodynamic status in patients in distributive shock and shock due to reduced cardiac output For bronchospasm occurring during anesthesia Isoproterenol hydrochloride injection is a beta-adrenergic agonist indicated: To improve hemodynamic status in patients in distributive shock and shock due to reduced cardiac output ( 1 ) For treatment of bronchospasm occurring during anesthesia ( 1 )

• Initiate isoproterenol hydrochloride injection at the lowest recommended dose and increase gradually based on patient response Recommended initial dosage: Shock: 0.5 mcg to 5 mcg per minute as an intravenous infusion Bronchospasm: 10 mcg to 20 mcg intravenous injection General Considerations Inspect visually for particulate matter and discoloration prior to administration, whenever solution and container permit
• Do not use if the injection is pinkish or darker than slightly yellow or contains a precipitate
• Discard any unused portion
• Diluted solution should be used immediately
• Unused material should be discarded
• Recommended Dosage Dosage should generally be started at the lowest recommended dose and increased gradually based on patient response
• Recommended dosage for adults with shock and hypoperfusion states: Route of Administration Preparation of Dilution Concentrations up to 10 times greater have been used when limitation of volume is essential
• Infusion Rate Rates over 30 mcg per minute have been used in advanced stages of shock
• Intravenous infusion Dilute 5 mL (1 mg) in 500 mL of 5% Dextrose Injection, USP 0.5 mcg to 5 mcg per minute (0.25 mL to 2.5 mL of diluted solution) Adjust the rate of infusion based on heart rate, central venous pressure, systemic blood pressure, and urine flow
• If the heart rate exceeds 110 beats per minute, consider decreasing or temporarily discontinuing the infusion. …

Injection solution: single dose, clear glass vials containing isoproterenol in a clear, colorless solution; 1 mL containing 0.2 mg/1 mL (0.2 mg/mL) 5 mL containing 1 mg/5 mL (0.2 mg/mL) Injection: 0.2 mg/mL and 1 mg/5 mL (0.2 mg/mL) single dose vial ( 3 )

• Safety and efficacy of isoproterenol
• In pediatric patients have not been established
• Intravenous infusions of isoproterenol in refractory asthmatic children at rates of 0.05-2.7 μg/kg/min have caused clinical deterioration, myocardial necrosis, congestive heart failure and death
• The risks of cardiac toxicity appear to be increased by some factors [acidosis, hypoxemia, coadministration of corticosteroids, coadministration of methylxanthines (theophylline, theobromine) or aminophylline] that are especially likely to be present in these patients
• If I.V. …

Clinical studies of isoproterenol hydrochloride injection did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects in clinical circumstances. There are, however, some data that suggest that elderly healthy or hypertensive patients are less responsive to beta-adrenergic stimulation than are younger subjects. …

Isoproterenol hydrochloride injection is contraindicated in patients with: tachycardia ventricular arrhythmias angina pectoris Isoproterenol hydrochloride injection is contraindicated in patients with: Tachycardia ( 4 ) Ventricular arrhythmias ( 4 ) Angina pectoris ( 4 )

Table 1. Clinically Relevant Interactions with Isoproterenol Epinephrine Clinical Impact Both drugs are direct cardiac stimulants, and their combined effects may induce serious arrhythmias upon simultaneous administration. Intervention Isoproterenol hydrochloride injection and epinephrine should not be administered simultaneously. Drugs that may potentiate clinical response of Isoproterenol Clinical Impact The effects of isoproterenol may be potentiated by tricyclic antidepressants, monoamine oxidase inhibitors, levothyroxinesodium, and certain antihistamines, notably chlorpheniramine, tripelennamine, and diphenhydramine. …

Cardiac arrhythmias and ischemia may be induced by isoproterenol hydrochloride injection ( 5.1 ) Sulfite: Isoproterenol hydrochloride injection contains metabisulfite, which may cause allergic reaction ( 5.2 ) 5.1 Cardiac Arrhythmias and Ischemia Isoproterenol may induce cardiac arrhythmias and myocardial ischemia in patients, especially patients with coronary artery disease, or cardiomyopathy. 5.2 Allergic Reactions associated with Sulfite Isoproterenol hydrochloride injection contains sodium metabisulfite, which may cause mild to severe allergic reactions including anaphylaxis or asthmatic episodes, particularly in patients with a history of allergies. …

The following adverse reactions have been associated with use of isoproterenol. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency reliably or to establish a causal relationship to drug exposure. Nervous system disorders: Nervousness, headache, dizziness, visual blurring Cardiovascular: Tachycardia, tachyarrhythmias, palpitations, angina, ventricular arrhythmias, Adams-Stokes attacks, pulmonary edema Respiratory: Dyspnea Other: Flushing of the skin, sweating, mild tremors, pallor, nausea Common adverse reactions with isoproterenol include tachycardia and palpitations ( 6 ) To report SUSPECTED ADVERSE REA …

8.1 Pregnancy Risk Summary Prolonged experience with isoproterenol use in pregnant women over several decades, based on published literature, do not identify a drug associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. However, there are risks to the mother and fetus associated with isoproterenol use during labor or delivery (see Clinical Considerations ) . …

Overdosage of isoproterenol can cause tachycardia or other arrhythmias, palpitations, angina, hypotension, or hypertension. In case of overdosage, reduce the rate of administration or discontinue isoproterenol hydrochloride injection until patient’s condition stabilizes. Monitor blood pressure, pulse, respiration, and EKG. It is not known whether isoproterenol hydrochloride is dialyzable.

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.