We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is Isoproterenol?

By C.B. Fox
Updated May 17, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Isoproterenol, also called isoproterenol hydrochloride or isuprel, is a medication that is structurally similar to epinephrine. It helps smooth muscles to relax and increases activity in the heart. Opening bronchial pathways that constrict while a patient is under anesthesia is the most common use for this medication. It starts to work quickly and wears of within a few hours.

Patients who experience bronchospasm can be given isoproterenol to make it easier for them to breathe. Bronchospasm can be caused by an allergic reaction, an asthma attack, or as a symptom of a disease. In this condition, small air passageways, called bronchioles, which are normally only about 0.04 inches (1 mm) in diameter, constrict under the pressure of the muscles around them. Patients who are under anesthesia can be at risk for bronchospasm, and isoproterenol may be administered while a patient is unconscious in order to counteract the condition.

The body has its own remedy for this condition, in the form of adrenaline. This hormone helps the airways to dilate, but once the adrenaline is used up, it is possible for the airways to close again. Epinephrine-like drugs, such as isoproterenol, act in a similar fashion to adrenaline, opening up restricted airways and allowing a patient to breathe normally.

Isoproterenol is also occasionally given to patients who have suffered a cardiac arrest, either as a stop gap treatment until defibrillation can be administered or as a treatment if defibrillation is unnecessary. Additionally, this medication may be used as a part of a treatment for patients who are in shock. In some cases, the drug may also be administered as an inhalant to control symptoms in patients who have chronic bronchitis or asthma.

Unlike epinephrine, isoproterenol specifically targets only certain β receptors in the body. It binds to both β1 and β2 receptors, which increase heart rate and relax the smooth muscles around the bronchial passageways respectively. Epinephrine also stimulates these same β receptors, though it targets certain α receptors as well.

Isoproterenol begins working within a few minutes. After it is administered, a patient’s bronchial passageways open, heart rate rises, and the diastolic blood pressure falls which allows blood to flow more easily through the body. Many patients may also experience heart palpitations, increased alertness and nervousness. This is due to the fact that the drug mimics adrenaline, which is responsible for the “fight or flight” response. The effects of isoproterenol wear off within about three hours.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

By robbie21 — On Dec 04, 2011

@jholcomb - It usually is not used for asthma. It was used more in the past, but was associated with a risk of death is asthma patients. Today's drugs for asthma are much safer and more effective than drugs used in the past. (Can you imagine having to take prednisone to control your asthma? *Shudders.*)

I'm not sure in what circumstances they would use this drug for asthma today. Perhaps in unusual circumstances like a patient with a very specific kind of asthma, a lot of allergies to other drugs, someone with a life-threatening attack, something like that.

You're right--today, most people with asthma carry albuterol (Ventolin) for their fast-acting inhaler and if they need a control medicine, they'll take something like Flovent (or Advair if their asthma is very serious), inhaled steroids. Unfortunately, the inhaled steroids are expensive - they are not yet available in generic.

By jholcomb — On Dec 04, 2011

I haven't heard of this particular drug being used for asthma. My understanding was that fast-acting inhalers were basically bronchodilators, and control medications were most often steroids (preferably inhaled) to control inflammation. What are the circumstances when this drug would be used for asthma?

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.