A comparison of blood loss caused by two prolonged-release formulations of indomethacin ('Flexin Continus' and 'Indocid' R) in normal healthy male volunteers.

Faecal blood loss arising from two prolonged-release formulations of indomethacin was compared in a double-blind, parallel group study in 12 healthy male volunteers. After a 1-week run-in period on placebo, subjects were allocated at random to receive 150 mg indomethacin per day, either as controlled-release 'Flexin Continus' tablets or as slow-release 'Indocid' R capsules, for 2 weeks and followed up for a further 1 week. Faecal specimens were collected over a 4-day period in each week and blood loss calculated using a 51Chromium-labelled red cell count method. Mean blood loss during the placebo run-in period was 2.6 ml/4 days in both study groups. Mean blood loss during treatment Weeks 2 and 3 with 'Flexin Continus' was 8.6 ml/4 days and 7.9 ml/4 days, respectively, and during treatment with 'Indocid' R capsules was 13.9 ml/4 days and 14.2 ml/4 days, respectively. There was a carry-over effect from both preparations as seen by a steady decrease in blood loss during the week after treatment. The mean value for 'Flexin Continus' was 6.9 ml/4 days and for 'Indocid' R was 8.3 ml/4 days during the wash-out week. Faecal blood loss was not statistically significantly different between the two formulations. No significant deterioration in haematological or biochemical results occurred in either group. Adverse symptoms were less frequent with 'Flexin Continus' tablets.