Inhibitors of prostaglandin synthesis block the inducible
cyclo-oxygenase COX-2 and thereby affect
the number of myometrial gap junctions and the
release of intracellular calcium (Figure 4). Indo -
methacin is the best-tested agent in this class, but
selective COX-2 inhibitors are also used. A recent
meta-analysis concluded that prostaglandin inhibitors
are superior to all other tocolytic agents with
respect to both efficacy and safety and are thus the
drugs of first choice for premature labor before the
32nd week of gestation (27).