the effects of roxatidine acetate hoe760 on 24hour intragastric acidity in healthy volunteers comparison with ranitidine and placebo in a series of doubleblind randomized studies in normal volunteers using continuous intragastric ph monitoring the effects of different dosage regimens of roxatidine a new h2receptor antagonist were compared with placebo and ranitidine roxatidine acetate 75 mg twice daily decreased median 24 h gastric acidity from ph 16 to 32 and median nocturnal acidity from 15 to 30 roxatidine acetate 150 mg at bedtime raised median 24 ph of the same 17 subjects to 24 and nocturnal ph to 59 in another series of experiments 150 mg roxatidine acetate at bedtime was as effective as ranitidine 300 mg nocte raising median nocturnal ph 14 volunteers from 14 to 665 compared to 67 respectively however when drugs were taken after the evening meal post cenam nocte pcn roxatidine acetate 150 mg was less potent than ranitidine 300 mg with median nighttime ph rising from 13 to 32 and 40 respectively in 28 volunteers roxatidine acetate 300 mg pcn raised the ph to 49 suggesting that roxatidine is 12 times as potent as ranitidine on a milligramformilligram basis