A systematic review including 5 RCTs (2 double-blind) with a total of subjects was abstracted in DARE.
Studies without endoscopic therapy (n=3): Omeprazole was associated with a statisticallly significantly lower risk of rebleeding compared with placebo in 1 trial (9% vs 35%). There was a trend toward lower rebleeding rates with omeprazole compared with ranitidine in the second trial (21% vs 39%), and no difference between omeprazole and placebo in the third trial (24% vs 27%).
Studies with endoscopic therapy (n=2): Rebleeding rates were similar where patients were given omeprazole or ranitidine in 1 trial. The second trial showed significantly lower rebleeding rate in patients treated with omeprazole compared with cimetidine (4% vs 24%).
Comment: The quality of evidence is downgraded by potential reporting bias.