Prevention of aspirin-induced fecal blood loss with oral prostaglandin E2: dose-response studies in man.

The purpose of this study was to determine the minimum effective protective dose of PGE2 given concurrently with ASA. Thirty-two adult male volunteers completed a double-blind placebo-controlled experiment. Fecal blood loss was measured by the 51Cr technique for 15 days. ASA (650 mg four times daily) was given for the middle 5 days and in addition subjects received PGE2 orally in doses of 0.04 mg, 0.25 mg or 0.5 mg or placebo four times daily. In the control group ASA caused a significant increase in fecal blood and this was reduced in a dose-dependent manner by the three doses of PGE2 employed. Serum salicylate was elevated similarly in all four groups. Four subjects receiving 0.5 mg PGE2 experienced mild transient side effects. It is concluded that concurrent treatment with oral PGE2 affords significant dose-dependent protection against ASA-induced gastrointestinal blood loss and that even a dose of 0.04 mg four times daily provided some protection.