Why are beta blockers contraindicated for ppl with asthma?

Published

Just wondering.

Up Vote Up Vote ×
Specializes in Community Health, Med-Surg, Home Health.

Beta Blockers can constrict the lungs.

Up Vote Up Vote ×

broncho spasm

leslie

Up Vote Up Vote ×

stimulation of beta 2 receptors causes broncho dilation. if you block these receptors, you can't broncho dilate as easily. when you have an asthma attack, a beta 2 agonist is usually given to induce broncho dilation. if you've blocked the beta receptors, this won't have too much of an effect.

i'm pretty sure that's why. feel free to correct me if i'm wrong though. i'm only halfway through my pharmacology class (pre-nursing).

Up Vote Up Vote ×

There are a few beta 1 selective beta blockers on the market.

Up Vote Up Vote ×
Specializes in Cardiac Telemetry, ED.

They're not contraindicated. They should be used *with caution* in people with asthma or other obstructive lung diseases, because they *can* cause bronchoconstriction.

Up Vote Up Vote ×
There are a few beta 1 selective beta blockers on the market.

so it's only the blocking of beta 2 receptors that they're trying to avoid with asthma pt's, correct? since a lot of the beta blockers used to treat hypertension are actually intended to block beta 1 receptors only - the beta 2 blocking is a side effect?

or is there a reason ALL beta blockers (specific and non-specific) are avoided with asthma pt's?

Up Vote Up Vote ×
Specializes in Homecare Peds, ICU, Trauma, CVICU.
so it's only the blocking of beta 2 receptors that they're trying to avoid with asthma pt's, correct? since a lot of the beta blockers used to treat hypertension are actually intended to block beta 1 receptors only - the beta 2 blocking is a side effect?

or is there a reason ALL beta blockers (specific and non-specific) are avoided with asthma pt's?

The heart contains beta 1 cells and the lungs contain beta 2 cells. Beta Blockers don't differentiate between beta 1 or 2, they block ALL beta cells, which is why they need to be used very cautiously in asthmatics, as they have a greater chance of experiencing bronchospasm. And to answer your question, you are correct in that beta blockers are not prescribed with the intention of blocking beta 2 (lung) cells, but that is the nature of the beast with these meds and why it is necessary to ask about lung disease when they are prescribed.

As someone said there are beta blockers that are beta 1 specific which can be safely used in asthmatics. But I don't know what they are off the top of my head.

Up Vote Up Vote ×
+ Join the Discussion