Do Asthma Medications Affect Blood Pressure?

doctor prescription
sturti/Getty Images

Asthma and high blood pressure (called hypertension) are both common health conditions, so it's no wonder if you (or a loved one) are concerned that your asthma medication is affecting your blood pressure.  

Unfortunately, the answer is not as cut and dry as you would probably like. In other words, it's a bit more complex than simply yes or no.  

Let's take a closer look at the mechanism of action behind asthma medications, and how this may affect a person's blood pressure.

Metered Dose Inhalers in Asthma: How They Work

Metered dose inhalers (MDIs) are a familiar and commonly prescribed asthma treatment. In fact, if you have asthma, the chances are almost 100 percent that MDIs are a familiar part of your treatment routine. This is because MDIs are fast acting and meant to be used as short-term relief from the sensations of chest tightness and breathing difficulty associated with sudden, minor asthma attacks.

The medicine in MDIs works by targeting molecules, called beta receptors, that line the walls of the respiratory passages. When stimulated by the medicine, these receptors cause the respiratory passages to expand, relieving asthma symptoms. Because of how it works, this medicine is called a beta-agonist (enhances the activity of beta receptors).

Beta receptors are also an important controller of blood vessel diameter, where their activation works to narrow the diameter of blood vessels.

In fact, you may have heard of beta blockers, a very common type of high blood pressure medicine. Beta blockers work by preventing the activation of blood vessel beta receptors. This means that the vessels stay more dilated (or widened) than normal, which lowers a person's blood pressure.

Asthma Medications: Effect on Blood Pressure

It makes sense to wonder about the effect asthma medications may have on blood pressure because of their beta-agonist activity.

In other words, if asthma medications stimulate beta receptor activity, and increased beta receptor activity causes increased blood pressure, then it's sensible to think that asthma medications increase blood pressure.

But the truth lies somewhere in the middle. If you were to directly expose blood vessels to the beta-agonist asthma medication, you would see some small amount of vessel constriction. However, this does not routinely occur in asthma patients using MDIs, and there are several reasons for this:

  • MDIs are an inhaled drug, and close to 100 percent of the drug remains within the lungs, and away from the beta receptors on blood vessels.
  • The beta agonist used in MDIs (albuterol) is selective (though not perfectly) for a subtype of a beta receptor that is found in large numbers on respiratory passages, but in much smaller numbers on blood vessels.
  • Albuterol has a very short timeframe of activity, so even though a small amount of the drug may find its way to blood vessels, and a small proportion of that drug may cause an effect on those vessels, the effect goes away quickly.

Along with the short-acting drug, albuterol, other beta-agonists, with longer life spans, are commonly used in the treatment of asthma.

These include drugs like fenoterol (intermediate lifespan, not used in the U.S.) and Severent (salmeterol), which has a long lifespan.

Though these drugs persist in the body for much longer than albuterol, they are still inhaled, tend to remain in the lungs, and don’t tend to work very well on the type of beta receptors found on blood vessels.

A Word From Verywell

The bottom line here is that while your asthma medication may transiently raise your blood pressure due to its beta-agonist activity, this is really not something you should worry about.

Even so, it's extremely important to devise an asthma management plan with your pulmonologist, allergist, or primary care physician.

Your plan should include the three following tips:

  • How to best avoid your unique asthma triggers.
  • A list of which medication you should take to prevent asthma symptoms (your inhaled corticosteroid) versus which medication you take to quickly relieve an asthma attack (your albuterol inhaler).
  • A step-by-step plan to help you know when you need to seek medical attention. 

On a final note, please tell your doctor all of the medications you are taking, as some may interact with your asthma medications like aspirin, nonsteroidal anti-inflammatories, or beta-blockers.

Sources:

American Academy of Allergy Asthma & Immunology. (2017). Medications and Older Adults.

Arboe B, Ulri CS. Beta-blockers: friend or foe in asthma? Int J Gen Med. 2013;6:549-55.

Drugs Affecting the Respiratory System. In: Pharmacology, 2nd Ed, Mycek, MJ, Harvey, RA, Champe, PC (Eds), Lippincott, Williams, and Wilkins, Philadelphia, PA 2000. p.217-222.

Continue Reading