Isoproterenol (Isuprel, Medihaler-Iso)

Category:

• Respiratory

Description:

• Antiasthmatic, bronchodilator, vasopressor, sympathomimetic

Indications:

• Mild or transient episodes of heart block and Stokes-Adams attacks (except when caused by ventricular tachycardia or fibrillation)

• Cardiac arrest (until electric shock or pacemaker is available)

• Bronchospasm occurring during anesthesia, asthma, chronic bronchitis, or emphysema

• Hypovolemic and septic shock, low cardiac output states, CHF, cardiogenic shock

Contraindications:

• Tachydysrhythmias, tachycardia or heart block caused by digitalis intoxication

• Ventricular dysrhythmias requiring inotropic therapy, angina pectoris

Precautions:

• Pregnancy category C

• Hypovolemia, coronary artery disease, coronary insufficiency

• Diabetes, hyperthyroidism

Adverse Reactions (Side Effects):

• CNS: anxiety, dizziness, headache, mild tremors, nervousness, weakness

• CV: angina, hypertension, hypotension, palpitations, tachycardia, tachydysrhythmias, ventricular dysrhythmias

• GI: nausea, vomiting

• RESP: pulmonary edema

• SKIN: flushing of skin, sweating

Dosage:

Administered orally (inhalation via solution and aerosol), intravenously, intramuscularly, subcutaneously

• Adult:            

  • Bronchospasm: 

    • MDI 1-2 puffs 4-6 times daily

    • NEB 0.25-0.5ml of a 1% solution diluted in 2-3ml normal saline or 0.25% and 0.5% undiluted, treatment may be repeated up to 5 times daily

  • Dysrhythmia/heart block: 

    • IV 0.02-0.06mg (1-3ml of 1:50,000 dilution) bolus, followed by subsequent doses of 0.01-0.2mg (0.5-10ml op 1:50,000 dilution)

    • IV INF 5 mcg/min initially, titrate to desired response, usual range 2-20 mcg/min

    • IM 0.2mg (1ml of 1:5,000 dilution) initially, subsequent doses of 0.02-1mg (0.1-5ml of 1:5,000 dilution)

    • SC 0.2mg (1ml of 1:5,000 dilution) initially, subsequent doses of 0.15-0.2mg (0.75-1ml of 1:5,000 dilution)

    • IC 0.02mg (0.1ml of 1:5,000 dilution)

  • Shock: 

    • IV INF 0.5-5 mcg/min (0.25-2.5ml of 1:500,000 dilution), titrate to patient response

• Child:            

  • Bronchospasm: 

    • MDI 1-2 puffs up to 6 times daily; NEB 0.01 ml/kg of 1% solution; minimum dose 0.1 ml, max dose 0.5ml diluted in 2-3ml normal saline

  • Shock: 

    • IV INF 0.05-2 mcg/kg/min, rate (ml/hr) = dose (mcg/kg/min) X weight (kg) X 60 min/hr divided by concetration (mcg/ml)