Beta Agonists

Question 1

Within the respiratory system, which receptor is very important?

Answer 1

B2, with activation it causes bronchodilation -> Increases cAMP which inhibits contraction of airway smooth muscle

Question 2

What kinda of Beta agonists are used for acute attacks? Why?

Answer 2

SABA- short acting beta agonist, Albuterol/Terbutaline, because they work immediately

Question 3

SABA’s ADRs

Answer 3

Albuterol, Terbutaline

-Lower ADR vs. higher with oral administration
-Increase HR (dose limiting)
-restlessness
-Insomnia
-Hypokalemia at high doses

Question 4

What are prophylaxis options for asthmatics? why?

Answer 4

Inhaled steroid + LABA, because it takes 15-20 minutes to work.

Question 5

Why is B2 agonist continuous nebulization therapy preferred to s.c. epinephrine?

Answer 5

Epinephrine is a MIXED agonist.
It will hit, B2, B1 and A1

Question 6

What is the block box warning for beta agonists?

Answer 6

LABA- down-regulation/desensitization of B2 receptors result in lowering responsiveness, BUT LABA + ICS are the standard of care.

Now, no blackbox warning for LABA + ICS

Blackbox warning for monotherapy LABA stays