• β₂ agonist
• synthetic sympathomimetric
• synthetic catecholamines

stimulates β₂ receptors in smooth muscles of bronchial tree - activates intracellular enzyme adenyl cylase which converts ATP to c-AMP

increases c-AMP levels is assoc. w/ smooth muscle relaxation and inhibition of mediation release from mast cells --> bronchial dilation

onset - within minutes

duration -  4-6 hours

tachycardia (small amount of β₁ effect)

skeletal muscle tremors - inhaled med concentrates in lungs, oral has increased dosage - more likely to cause tremors

Terbutaline - D + A

Adults

0.25 mg SQ may repeat in 20-30 min

alt. route 1-2 mg in 3 cc NSS nebulized

Terbutaline - D + A

Pediatric

longer duration than epi wehn given SQ

greater bronchodilation prop.s, less burning pain upon injection, seldom used in older adult patients (>30 y/o)