In tachysystole management during labor, which medication might be used as a tocolytic?

• A. Nifedipine
• B. Terbutaline
• C. Magnesium sulfate
• D. Hydralazine

Answer: (B)

Tocolysis aims to calm the uterus when contractions become overly frequent, protecting the fetus from distress. Terbutaline fits this need as a fast-acting tocolytic. It’s a beta-adrenergic agonist that targets the uterine smooth muscle; by stimulating beta-2 receptors, it increases cAMP inside the cells, causing relaxation and a rapid drop in contraction frequency and strength. In tachysystole management, after stopping oxytocin and addressing immediate factors, terbutaline can be given to halt ongoing contractions and restore fetal tolerance. Monitor closely for maternal side effects like tachycardia, palpitations, tremor, or hyperglycemia, and use with caution in patients with certain cardiac conditions. Hydralazine is not a tocolytic, and while nifedipine and magnesium sulfate can have tocolytic effects in other contexts, terbutaline is the classic fast-acting option highlighted for acute tachysystole.