[Weak transplacental passage of prazosin (Alpress) during the third trimester of pregnancy. 3 cases]

Prazosin is a selective peripheral alpha 1-adrenoceptor antagonist used in the treatment of hypertension and heart failure. This drug has the disadvantage of relatively short terminal half-life (of the order of 2 to 3 hours); its wide use has been limited by the number of daily administrations. Recently, a new formulation of prazosin has been commercialized i.e., prazosin-gastrointestinal therapeutic system (P-GITS) given once daily in doses of either 2.5 or 5.0 mg (i.e., Alpress). The potential suitability of this controlled-release system as treatment of hypertension during pregnancy seems important. However, the possible transplacental passage of PRZ was unknown. We aimed to study this phenomenon in three pregnant women given a once daily 5 mg dose of P-GITS during the third trimester of pregnancy. There is a slight transplancental passage of prazosin i.e., of the order of 10 to 20% of the maternal concentration level determined at the same time. Concerning neonatal outcome, no problems were noted and the babies left the hospital in good health. Prazosin-GITS offers a new approach to control and improve the outcome of hypertensive therapy during pregnancy.