| Indication | For the treatment and prophylaxis of premature labour |
| Pharmacodynamics | Beta-2 adrenergic receptors are located at sympathetic neuroeffector junctions of many organs, including uterus. Ritodrine is beta-2 adrenergic agonist. It stimulates beta-2 adrenergic receptor, increases cAMP level and decreases intracellular calcium concentration. The decrease of calcium concentration leads to a relaxation of uterine smooth muscle and, therefore, a decrease in premature uterine contractions. |
| Mechanism of action | Ritodrine is beta-2 adrenergic agonist. It binds to beta-2 adrenergic receptors on outer membrane of myometrial cell, activates adenyl cyclase to increase the level of cAMP which decreases intracellular calcium and leads to a decrease of uterine contractions. |
| Absorption | Not Available |
| Volume of distribution | Not Available |
| Protein binding | ~56% |
| Metabolism | Hepatic, by both the mother and fetus |
| Route of elimination | Not Available |
| Half life | 1.7-2.6 hours |
| Clearance | Not Available |
| Toxicity | LD50=64mg/kg (mice, IV); LD50=540 mg/kg (mice, oral); LD50=85 mg/kg (rat, IV) |