What drug class does nifedipine belong to, which can be used as a tocolytic agent?

Nifedipine belongs to the class of calcium channel blockers, which makes it effective as a tocolytic agent for the management of preterm labor. Tocolytic agents are medications used to suppress premature contractions of the uterus.

Calcium channel blockers work by inhibiting the influx of calcium ions into cardiac and smooth muscle cells, leading to relaxation of the vascular smooth muscle and a decrease in muscle contractions, including those of the uterus. This relaxation helps to delay preterm labor by slowing down or stopping uterine contractions. Nifedipine specifically has been shown to be effective in reducing uterine activity and prolonging pregnancy in cases of threatened preterm labor.

Other drug classes, such as beta-adrenergic agonists, also serve as tocolytic agents, but they operate through different mechanisms. Antihistamines and prostaglandins are not used for tocolysis; antihistamines primarily target allergic reactions, and prostaglandins can induce labor rather than prevent it. Therefore, the classification of nifedipine as a calcium channel blocker accurately reflects its role in tocolysis.