EFFICACY OF MISOPROSTOL IN CONTROLLING INDOMETHACIN-INDUCED FECAL BLOOD-LOSS IN ARTHRITIC PATIENTS

Indomethacin, a nonsteroidal anti-inflammatory drug, may cause gastric mucosal damage as shown by fecal blood loss. A randomized, double-bli nd, placebo-controlled, parallel group study was conducted to determin e the effects of 400 mcg b. i. d. misoprostol, a synthetic prostagland in E1 analog, on intestinal blood loss caused by 50 mg t. i. d. indome thacin. Forty-two arthritic patients, mean age 59 years, received indo methacin for 14 days. Those with baseline blood loss of at least 1.5 m l/day during the first 7 days were randomized to 400 mcg of misoprosto l or placebo (days 8 to 14). Fecal blood loss was measured using Cr-51 labelled red blood cell technique. Success was defined as a reduction in mean daily blood loss of at least 50% during the treatment period compared to mean daily blood loss during the baseline (pre-treatment) phase. The mean daily blood loss on treatment days 9-15 was not signif icantly reduced from baseline in either group. These data neither conf irm nor deny the effectiveness of misoprostol in reducing fecal blood loss caused by indomethacin. The results may have been confounded by t he administration of misoprostol twice daily while indomethacin was ad ministered three times daily. In addition, fecal blood loss as an indi cator of gastrointestinal mucosal damage is not a sensitive measure; i t is characterized by poor reproducibility and wide fluctuations withi n individual responses. Inappropriate laboratory techniques may have f urther reduced the sensitivity and reliability of this procedure.