Intravenous administration of lansoprazole: a preliminary study of dose ranging and eflcacy in upper gastrointestinal bleeding

Using 24-h pH monitoring, we studied the optimal dose and mode of administration of lansoprazole (LAN) injection in healthy adult male volunteers in three tests of antisecretory effect. We followed this with a dose-finding study, using the drug's suppressive effect on increased gastric acid secretion due to surgical stress as the indicator. Finally, we conducted a pilot study to determine the optimal mode of administration and efficacy of the drug in patients with haemorrhage from the upper gastrointestinal tract. Twenty-four-hour intragastric pH monitoring established the order of potency of the different regimens: LAN 30 mg b.d. > LAN 15 mg b.d.; and LAN 30 mg b.d., intravenous drip infusion = LAN 30 mg b.d., bolus injection. Lansoprazole 30 mg b.d. appeared to be slightly more effective than LAN 15 mg b.d. in suppressing increased gastric acid secretion due to post-operative stress and in haemostasis in patients with upper gastrointestinal bleeding. No severe adverse effects were observed in either study.