Isoproterenol

Isoproterenol is a prescription medication used to treat Adams-Stokes Attacks, Cardiac Arrest, or Heart Block, Shock, and Bronchospasm during Anesthesia. 

• Isoproterenol is available under the following different brand names: Isuprel

Adult and pediatric dosage

Injectable solution

• 0.2mg/mL

Adams-Stokes Attacks, Cardiac Arrest, or Heart Block

Adult dosage

• IV bolus: 0.02-0.06 mg (1-3 mL of a 1:50,000 dilution), initially, then doses of 0.01-0.2 mg
• IV infusion: 5 mcg/min (1.25 mL of a 1:250,000 dilution), initially, then doses of 2-20 mcg/min based on patient’s response

Shock

Adult dosage

• 0.5-5 mcg/min (0.25-2.5 mL of a 1:250,000 dilution) IV infusion

Bronchospasm During Anesthesia

Adult dosage

• 0.01-0.02 mg IV repeat as needed

Postoperative Cardiac Patients with Bradycardia

Pediatric dosage

• IV infusion: 0.029 mcg/kg/min

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”.

Common side effects of Isoproterenol include:

• headache, 
• dizziness, 
• nervousness, 
• nausea, 
• blurred vision, 
• tremors, 
• sweating, and
• flushing (sudden warmth, redness, or tingly feeling)

Serious side effects of Isoproterenol include:

• hives, 
• difficulty breathing, 
• swelling of the face, lips, tongue, or throat, 
• pounding heartbeats, 
• fluttering in the chest, 
• chest pain, 
• severe headache, 
• pounding in the neck or ears, 
• pain while breathing, 
• shortness of breath, 
• cough, 
• pale skin, 
• cold and clammy skin, 
• anxiety, and 
• lightheadedness

Rare side effects of Isoproterenol include:

• none 

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first

• Isoproterenol has severe interactions with the following drugs:
  • isocarboxazid
  • linezolid
  • phenelzine
  • procarbazine
  • selegiline transdermal
  • tranylcypromine
• Isoproterenol has serious interactions with at least 26 other drugs. 
• Isoproterenol has moderate interactions with at least 238 other drugs. 
• Isoproterenol has minor interactions with at least 29 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drugs interactions. Therefore, before using this drug, tell your doctor or pharmacist of all the drugs you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Contraindications

• Hypersensitivity, digitalis intoxication, angina pectoris, preexisting cardiac arrhythmias (particularly ventricular arrhythmias that require inotropic treatment and tachyarrhythmias). 

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Isoproterenol?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Isoproterenol?”

Cautions

• Use caution in patients with convulsive disorders, renal disease, CAD, coronary insufficiency, DM, HTN, hyperthyroidism, hyperresponsiveness to sympathomimetic amines, elderly
• May cause thyroid storm in susceptible patients with hyperthyroidism
• May transiently increase blood glucose levels

Cardiac effects

• Isoproterenol hydrochloride injection should be started at the lowest recommended dose and gradually increased if necessary while carefully monitoring the patient; doses sufficient to increase heart rate to more than 130 beats per minute may increase the likelihood of inducing ventricular arrhythmias such increases in heart rate will also tend to increase cardiac work and oxygen requirements which may adversely affect failing heart or heart with a significant degree of arteriosclerosis
• Adequate filling of the intravascular compartment by suitable volume expanders is of primary importance in most cases of shock and should precede administration of vasoactive drugs; in patients with normal cardiac function, determination of central venous pressure is a reliable guide during volume replacement; if evidence of hypoperfusion persists after adequate volume replacement, isoproterenol hydrochloride injection may be given
• In addition to routine monitoring of systemic blood pressure, heart rate, urine flow, and electrocardiograph, monitor response to therapy by frequent determination of central venous pressure and blood gases
• Closely observe patients in shock during isoproterenol hydrochloride injection administration; if the heart rate exceeds 110 beats per minute, it may be advisable to decrease infusion rate or temporarily discontinue infusion
• Determinations of cardiac output and circulation time may also be helpful; take appropriate measures to ensure adequate ventilation; pay attention to acid-base balance and correction of electrolyte disturbances
• By increasing myocardial oxygen requirements while decreasing effective coronary perfusion isoproterenol hydrochloride injection may have a deleterious effect on the injured or failing heart
• Most experts discourage the use of the drug as an initial agent in treating cardiogenic shock following myocardial infarction; however, when low arterial pressure has been elevated by other means, isoproterenol hydrochloride injection may produce beneficial hemodynamic and metabolic effects
• In a few patients, presumably with organic disease of AV node and branches, the drug has paradoxically been reported to worsen heart block or to precipitate Adams-Stokes attacks during normal sinus rhythm or transient heart block
• The drug is no longer recommended for cardiac arrest

Pregnancy and Lactation

• Use with caution if the benefits outweigh the risks during pregnancy. 

Lactation

• Not known if excreted into breast milk, avoid.