Absence of Antidiuresis during Administration of Prostaglandin F ₂ α

Water diuresis was induced in six patients in mid-pregnancy. Three were then given oxytocin and the remainder prostaglandin F(2)alpha (PGF(2)alpha), both drugs being infused intravenously in doses used to induce labour at term. Pronounced antidiuresis occurred with oxytocin, whereas PGF(2)alpha showed no such effect. The probable absence of any risk of water intoxication when using PGF(2)alpha in inducing labour may be of particular value when maternal pre-eclampsia or renal disease is present.