About Ritodrine A Beta-2 adrenergic agonist, A tocolytic(uterine relaxant). Mechanism of Action of Ritodrine Ritodrine is 2 adrenergic agonist. It binds to ?2 adrenergic receptor on outer membrane of myometrial cell and activates adenylyl cyclase. This will result in an increase in cyclic adenosine monophosphate (cyclic AMP) level and decreases intracellular calcium concentration. The decrease of calcium concentration leads to a relaxation of uterine smooth muscle. Indications for Ritodrine 1. Management of preterm labour