What is the mechanism of action of Nifedipine as a tocolytic?

The mechanism of action of Nifedipine as a tocolytic primarily involves its ability to block calcium channels. Nifedipine is a calcium channel blocker that works by inhibiting the entry of calcium ions into vascular smooth muscle and cardiac muscle. In the context of tocolysis, by decreasing calcium influx into uterine smooth muscle cells, Nifedipine reduces uterine contractions and helps in managing preterm labor.

Calcium is a crucial element for muscle contraction, and when its availability is reduced due to the action of calcium channel blockers, the smooth muscles of the uterus are less able to contract effectively. This leads to decreased uterine activity and helps to prevent preterm labor.

While increasing intracellular cAMP can also have effects on muscle relaxation, it is not the primary mechanism of action associated with Nifedipine in a clinical setting for tocolysis. Inhibition of cyclooxygenase pertains to non-steroidal anti-inflammatory drugs (NSAIDs) and does not relate to Nifedipine's action. Likewise, while decreased uterine contractility is an outcome of Nifedipine's action, it is not the underlying mechanism but rather a result of calcium channel blockade.