Ciprostene is the 9β-methyl analog of carbaprostacyclin and a stable analog of PGI2. Ciprostene exhibits biological activity similar to PGI2, but is 30-fold less potent. In patas monkeys, ciprostene induces hypotension and causes tachycardia when administered at a dose of 0.16 μg/kg/min.{4373} In addition, ciprostene inhibits ADP-induced platelet aggregation ex vivo and in vitro with ID50 values of 9.1 μg/kg/min and 60 ng/ml, respectively.{4373,4375}