Premature labour (after 20th week), prevention of premature labour after gynecological operations; acute fetal distress during labour if caused by hypermotility of the uterus or compression of the umbilical cord.

Ritodrine hydrochloride is a potent beta-2 stimulant which produces direct relaxation of the uterine smooth muscle and decreases the force and frequency of uterine contractions. Ritodrine is more specific on uterine and bronchiolar smooth muscle receptors than on those of the heart and vasculature. However, ritodrine's beta-2 specificity is dose related and at higher dosages other beta-sympathomimetic pharmacologic effects occur including cardiac stimulation, vasodilation, elevations of blood glucose and plasma insulin, muscle tremor, decreases in serum potassium and increases in fatty acids Ritodrine is used for the inhibition of premature labor. Ritodrine is most likely to be successful in patients with intact amniotic membranes and when therapy is initiated as soon as the diagnosis of preterm labor is established.

Bioavailability: IM - well; Protein binding: 32% to 38%; Renal excretion: 71% to 93%; Elimination Half-life: 60-156min; Hemodialysis or Peritoneal Dialyzable: Yes

Patients with heavy blood loss per vaginam, maternal cardiac disease, chorioamnionitis.

B

Infant risk cannot be ruled out.

Ritodrine administration has resulted in fetal and maternal tachycardia, plus increased blood pressure, lethargy, sleepiness, ketoacidosis, pulmonary edema, and erythema.

Premature labor: IV, initial dose 0.05mg/min to be gradually increased according to the results by 0.05mg/min every 10 minutes. The effective dosage: 0.15-0.35mg/min. The infusion should be continued for 12 to 48 hours after the uterine contraction have ceased.

D5W or NS is recommended as a diluent for ritodrine at concentration of 300mg/L.