PGF2.alpha.-NEt is an analog of PGF2.alpha. in which the C-1 carboxyl group has been modified to an N-ethyl amide. PG esters have been shown to have ocular hypotensive activity.{8837} PG N-ethyl amides were recently introduced as alternative prostaglandin ocular hypotensive prodrugs.{8941} Although it has been claimed that PG ethyl amides are not converted to the free acids in vivo