II. Indications

  1. Other inotropic agents (Dobutamine, Amrinone) are preferred over Isoproterenol
  2. Refractory and hemodynamically significant, Symptomatic Bradycardia (pulse present)
    1. Specific Uses
      1. Heart Block
      2. Bradycardia in denervated transplanted heart
    2. Unresponsive to other measures
      1. Atropine
      2. Epinephrine
      3. Transcutaneous Pacing or transvenous pacing
      4. Dopamine

III. Contraindications

IV. Precautions

  1. Decreases Diastolic Blood Pressure
    1. No alpha adrenergic effect
    2. Increases Heart Rate (less diastolic filling time)
  2. May precipitate Myocardial Ischemia
    1. Increases myocardial oxygen demand
    2. Decreases coronary perfusion
  3. Induces Arrhythmias
    1. Ventricular Tachycardia
    2. Ventricular Fibrillation
  4. Exacerbates tachyarrhythmias due to Digitalis Toxicity
  5. Precipitates Hypokalemia

V. Dosing: Pediatric Infusion (Same as Epinephrine preparation)

  1. Preparation
    1. Draw up "x" mg of Isoproterenol
    2. Where "x" = 0.6 x Weight in Kilograms
    3. Add enough D5W or NS for 100 ml total
    4. At this dilution:
      1. Infusion rate of 1 ml/h provides 0.1 ug/kg/min
  2. Start Dose: 10 ml/hour (10 ug/kg/min)
  3. Titrate to clinical response, adjusting every 5 min

VI. Mechanism

  1. Synthetic Sympathomimetic amine
  2. Pure Beta Adrenergic Agonist
    1. Potent Chronotropic effects (b1)
      1. Increases Heart Rate (more than Epinephrine)
      2. Potentiates AV conduction
    2. Potent Inotropic effects (b1)
      1. Increases cardiac contractility
      2. Markedly increases Cardiac Output
    3. Potent peripheral vasodilatation (b2)
      1. Decreases Diastolic pressure and mean arterial pressure
    4. Bronchodilation (b2)
    5. Endocrine
      1. Increased Serum Glucose via glycogenolysis and Gluconeogenesis (b2)
      2. Increased fat breakdown via lipolysis of Triglycerides (b1)
    6. Other
      1. Decreased intestinal tone and motility
      2. Decreases Mast Cell release
  3. Markedly increases myocardial oxygen demand (b1)
    1. May provoke Myocardial Ischemia
    2. May decrease coronary perfusion

VII. Pharmacokinetics

  1. Very short Half-Life (<1.5 minutes)
    1. As with other Catecholamines, rapid metabolism by COMT (but minimal metabolism by MAO)

VIII. Dosing

  1. Preparation
    1. Dissolve 1 mg Isoproterenol in 250 ml D5W (4 mcg/ml, 75 ml/h = 5 mcg/min) OR
    2. Dissolve 2 mg Isoproterenol in 250 ml D5W (8 mcg/ml, 37.5 ml/h = 5 mcg/min)
  2. Adult Infusion
    1. Start Dose: 2 mcg/min IV
    2. Titrate: 2-10 mcg/min to clinical response
      1. Target Heart Rate over 60 beats per minute
    3. Maximum: 20 mcg/min
  3. Pediatric Infusion
    1. Start Dose: 0.05 mcg/kg/min IV
    2. Titrate: Increase by 0.1 mcg/kg/min every 5 to 10 minutes to clinical response
      1. Target Heart Rate over 60 beats per minute
    3. Maximum: 2 mcg/kg/min up to 20 mcg/min (or signs of toxicity)

IX. Safety

  1. Unknown safety in Lactation
  2. Pregnancy Category C

XI. References

  1. Hamilton (2020) Tarascon Pocket Pharmacopoeia
  2. Olson (2020) Clinical Pharmacology, Medmasters, Miami, p. 13-33
  3. Goldstein (2010) Clin Auton Res 20(6):331-52 +PMID: 20623313 [PubMed]

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Ontology: Isoproterenol (C0022245)

Definition (NCI) A synthetic catechol compound and potent beta adrenergic agonist with peripheral vasodilator, bronchodilator, and cardiac stimulating properties. Isoproterenol exerts its effect on the beta-1 adrenergic receptors in the myocardium, thereby increasing heart rate and cardiac output. In addition, isoproterenol acts on beta-2 adrenergic receptors in bronchiolar and vascular smooth muscle, thereby causing smooth muscle relaxation.
Definition (MSH) Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.
Definition (CSP) synthetic adrenergic agent derived from norepinephrine, having powerful bronchodilator and cardiac stimulant action.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D007545
SnomedCT 57845006, 372781009
English Isoprenaline, Isopropyl Noradrenaline, Isopropylarterenol, Isopropylnoradrenaline, Isoproterenol, Noradrenaline, Isopropyl, 4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol, 1,2-Benzenediol, 4-(1-hydroxy-2-((1-methylethyl)amino)ethyl)-, Isopropylnorepinephrine, isoproterenol preparations (medication), isoproterenol preparations, Isoproterenol [Chemical/Ingredient], isopropylnorepinephrine, isoproteronol, isoprenaline, isoproterenol, ISOPROTERENOL, Isoproteronol, Isoproterenol (product), Isoproterenol (substance)
Swedish Isoproterenol
Czech isoprenalin, isoproterenol
Finnish Isoprenaliini
French Isoprotérénol, Isoprénaline
Russian DSU, IZADRIN, IZOPROPILARTERENOL, IZUPREL, IZOPRENALIN, DIKHLORIZOPROTERENOL, IZOPROPILNORADRENALIN, IZOPROTERENOL, ДИХЛОРИЗОПРОТЕРЕНОЛ, ДСУ, ИЗАДРИН, ИЗОПРЕНАЛИН, ИЗОПРОПИЛАРТЕРЕНОЛ, ИЗОПРОПИЛНОРАДРЕНАЛИН, ИЗОПРОТЕРЕНОЛ, ИЗУПРЕЛ
Japanese ジクロロイソプロテレノール, 硫酸イソプレナリン, イソパール, イソプロテレノール, イソプロピルアルテレノール, イソプロピルノルアドレナリン, イソメニール, スーナー, スーナーL, メジヘラーイソ, イソパールP, 塩酸イソプレナリン, プロタノール, L-イソプレナリン塩酸塩, プロタノールL, メジヘラー・イソ, プロタノールS, L-塩酸イソプレナリン, イソプロピルノルエピネリン, セダンゾール"イソ", アスプール, イソプレナリン
Spanish isoprenalina (producto), isoprenalina, isoproterenol, isoproterenol (producto), isoproteronol, isoprenalina (sustancia), isoproterenol (sustancia), Isoprenalina, Isopropilarterenol, Isoproterenol
Polish Izoproterenol, Izoprenalina
German Isoprenalin, Isopropylarterenol, Isoproterenol
Italian Isoproterenolo
Portuguese Isoprenalina, Isopropilarterenol, Isoproterenol