Final answer:
Ritodrine (Yutopar) and Terbutaline (Brethine) are tocolytic agents used to prevent preterm birth.
Step-by-step explanation:
Ritodrine (Yutopar) and Terbutaline (Brethine) are tocolytic agents used to prevent preterm birth. They work by relaxing the smooth muscles of the uterus, which helps to delay contractions and prolong pregnancy in cases of preterm labor. These medications are typically administered via injection or oral tablets under the supervision of a healthcare professional.