For a study, researchers sought to compare the effectiveness of oral nifedipine versus parenteral isoxsuprine in preventing preterm labor. A comparative analysis was required given the scarcity of studies comparing these 2 agents. About 80 antenatal women between the ages of 28 and 37 weeks with regular uterine contractions, cervical dilatation of less than or equal to 3 cm, and less than 50% cervical effacement, were randomly assigned to receive either 40 mg isoxsuprine or 20 mg nifedipine. The drugs’ efficacy was measured in terms of preterm labor arrest, pregnancy lengthening, and the number of days gained by the infant before birth. In comparison to nifedipine, isoxsuprine showed increased lowering of systolic blood pressure (SBP), diastolic blood pressure (DBP), and slightly higher maternal pulse rate but higher fetal pulse rate (P<0.05). Isoxsuprine was associated with significantly more side effects. The nifedipine group had a longer pregnancy (25 days) than the isoxsuprine group (19 days) (P<0.05). The neonates in group B had a higher birth weight than those in group A (P<0.05). Compared to neonates in group A, none of the neonates in group B had an abnormal Appearance, Pulse, Grimace, Activity, and Respiration (APGAR) score of less than 7 at 5 minutes after birth. The majority of the neonates in the group. When compared to group B, group A had tachycardia and respiratory distress syndrome (RDS) (17.5% and 12.5%, respectively). Group B had a higher overall success rate (86.8%) than Group A (80%). Compared to isoxsuprine, nifedipine was slightly more effective in preventing preterm labor with fewer side effects.

Source:journals.lww.com/jfmpc/Fulltext/2022/05000/Oral_nifedipine_and_parenteral_isoxsuprine_in.42.aspx