Lansoprazole. A review of its pharmacodynamic and pharmacokinetic properties and its therapeutic efficacy in acid-related disorders

The treatment of Helicobacter pylori infection in the management of peptic ulcer disease

Antimicrobial therapy against H. pylori is indicated for all patients with documented peptic ulcer disease who have evidence of the infection. The regimen of first choice, selected on the basis of available studies, is triple therapy with bismuth, metronidazole, and tetracycline (Table 1). For patients who are known to have taken metronidazole previously, clarithromycin may be substituted for metronidazole. For patients with active, symptomatic peptic ulcers we also recommend an antisecretory drug to promote healing and relieve symptoms. Second-choice regimens consist of combinations of two antimicrobial drugs--metronidazole, amoxicillin, or clarithromycin--with an antisecretory agent, preferably an H+/K+-ATPase antagonist such as omeprazole. The combination of a single antimicrobial drug (especially amoxicillin) with omeprazole is less efficacious and cannot be recommended. Regardless of the antimicrobial regimen used, successful eradication of H. pylori infection markedly reduces the risk of recurrent peptic ulcers. If this therapeutic approach is taken with all patients with peptic ulcers, the recurrence of ulcers should become a rarity in medical practice.

GR122311X (ranitidine bismuth citrate), a new drug for the treatment of duodenal ulcer

BACKGROUND

Ranitidine bismuth citrate (GR122311X) is a new drug which offers potential benefits in healing duodenal ulcers and prevention of relapse.

METHODS

This randomized, multi-centre double-blind study of 1620 patients compared the effect of 4 weeks of treatment with GR122311X 200 mg b.d. (n = 401), 400 mg b.d. (n = 404) or 800 mg b.d. (n = 404) or ranitidine hydrochloride 150 mg b.d. (n = 411) on the rates of duodenal ulcer healing and of overall success (ulcers healed and remaining ulcer free in the 24-week follow-up phase).

RESULTS

All four treatments were equally effective at ulcer healing (79%, 85%, 84% and 81% of patients, respectively). GR122311X 400 mg b.d. (38%) and 800 mg b.d. (37%) were significantly more effective than ranitidine hydrochloride 150 mg b.d. (32%) with respect to overall success (P = 0.050 and P = 0.030, respectively) but there was no difference with GR122311X 200 mg b.d. (31%). GR122311X caused effective, dose-related suppression of H. pylori (47%, 61% and 74%); H. pylori eradication rates were 18%, 21% and 22%. GR122311X was safe and well tolerated, with an adverse event profile similar to that of ranitidine hydrochloride 150 mg b.d. Median week 4 trough plasma bismuth levels were 1.3 ng/mL, 2.3 ng/mL and 3.3 ng/mL with GR122311X 200 mg b.d., 400 mg b.d. and 800 mg b.d. respectively. No individual plasma bismuth concentrations were of clinical concern.

CONCLUSIONS

GR122311X is a safe and effective ulcer healing drug, and provides a platform on which anti-H. pylori therapy can be based.

Comparison of lansoprazole and omeprazole in the short-term management of duodenal ulcers in Taiwan

Lansoprazole is a novel H+/K+-ATPase inhibitor which exhibits a very potent and long-acting suppression of acid secretion. The object of this randomized, controlled trial was to compare duodenal ulcer healing rates after 4 weeks of treatment with a once-daily regimen of either 30 mg lansoprazole or 20 mg omeprazole. Of a total of 111 patients 57 received lansoprazole, whereas 54 received omeprazole. In intention-to-treat analysis at 4 weeks, 89.5% patients showed ulcer healing following treatment with lansoprazole compared with 83.3% of patients treated with omeprazole. Per protocol analysis indicated that 96.1% of patients treated with lansoprazole showed ulcer healing, compared with 93.6% of patients treated with omeprazole (NS). Age, smoking or ulcer size did not affect the ulcer healing rate. Both agents could effectively and quickly resolve ulcer symptoms. The Helicobacter pylori clearance was seen in 36 (73.5%) patients in the lansoprazole group and in 40 (80%) patients in the omeprazole group after four weeks of treatment (NS). In addition, both agents led to hypergastrinaemia, by approximately 1.6 fold. Adverse side effects included a few occurrences of reversible skin rash and constipation. It is concluded that lansoprazole elicits an adequate healing response and resolves symptoms of duodenal ulcer as well as omeprazole. Furthermore, lansoprazole is well tolerated with a few adverse side effects.

Comparison of pantoprazole versus omeprazole in the treatment of acute duodenal ulceration--a multicentre study

METHODS

In this randomized, double-blind, multicentre study, the proton pump inhibitors pantoprazole and omeprazole were compared in patients with active duodenal ulcers. Two hundred and seventy-six protocol-correct patients received either pantoprazole 40 mg (n = 185) or omeprazole 20 mg (n = 91), once daily for 2 or 4 weeks, depending on the progress of ulcer healing.

RESULTS

Rates of complete ulcer healing after 2 weeks were 71% in patients given pantoprazole and 74% in patients given omeprazole. After 4 weeks the figures were 96% and 91%, respectively. These differences were not significant. There was no significant difference in ulcer pain prior to treatment, and 85% of the pantoprazole group and 86% on omeprazole were pain-free after 2 weeks (not significant). The time until complete pain relief with pantoprazole or omeprazole, based on data from diary cards, was not significantly different (P > 0.05, Uleman's U-test). Both treatments were equally well tolerated. Changes in routine laboratory parameters were minimal in both groups.

CONCLUSION

Pantoprazole was shown to be a highly-effective and well-tolerated treatment for acute duodenal ulcer. Pantoprazole 40 mg and omeprazole 20 mg were equally effective with respect to ulcer healing and pain relief, and have similar adverse event profiles.

Pharmacokinetics of lansoprazole in hemodialysis patients

The pharmacokinetics of the new benzimidazole proton pump inhibitor lansoprazole and five of its metabolites were assessed after single oral dose administration to five hemodialysis patients. Patients were studied on dialysis and nondialysis days. Multiple blood and dialysate samples were collected after dosing and were assayed for lansoprazole and metabolite content via high-performance liquid chromatography. The degree of lansoprazole plasma protein binding was lower in hemodialysis patients than in subjects with normal renal function or patients with renal impairment not requiring dialytic therapy, although this tended to moderate when assessed immediately after dialysis. Examination of venous plasma concentration, paired arterial-venous concentration, and dialysate data revealed that lansoprazole and its metabolites were poorly dialyzable. No dosage adjustment of lansoprazole is necessary in hemodialysis patients nor is supplementation after hemodialysis sessions necessary.

Determination of lansoprazole and five metabolites in plasma by high-performance liquid chromatography

A high-performance liquid chromatographic method for the determination of lansoprazole, a new proton-pump inhibitor, and five of its metabolites in human plasma is described. Lansoprazole, its metabolites, and internal standard (omeprazole) were extracted into diethyl ether-methylene chloride and separation was obtained using a reversed-phase column under isocratic conditions. The method features monochromatic ultraviolet detection at 285 nm, and single extraction, single evaporation sample handling. The lower limit of quantitation, based on standards with acceptable coefficients of variation, was 10 ng/ml for all compounds. No endogenous compounds were found to interfere. This method has been demonstrated to be suitable for pharmacokinetic studies in humans.

Clinical pharmacokinetics of lansoprazole

Lansoprazole, a benzimidazole derivative with antisecretory and antiulcer activities, inhibits the acid pump activity at the final stage of the enzyme process and therefore reduces the acid secretion of parietal cells. Lansoprazole is converted to active metabolites in the acid environment of these cells. It is rapidly absorbed from a gastric acid-resistant formulation and is approximately 97% bound in human plasma. Single dose pharmacokinetics of lansoprazole appear to be linear over the range from 15 to 60mg. Food and time of dose influence absorption after single doses, but do not modify the antisecretory effect of multiple doses. Lansoprazole is extensively metabolised following oral administration into sulphone and 5-hydroxylated metabolites by the cytochrome P450 enzymes CYP3A4 and CYP2C18. Two other metabolites have been identified in plasma: sulphide and hydroxylated sulphone. Mean plasma elimination half-life (t1/2) is between 1.3 and 2.1 hours in healthy volunteers. 15 to 23% of the total dose is found in urine as free and conjugated hydroxylated metabolites, while unchanged lansoprazole is not detected. The pharmacokinetic profile of the drug is not modified by multiple administration. In healthy elderly volunteers, area under the plasma concentration-time curve (AUC) and t1/2 are significantly greater after single administration occurs to the same extent as in young volunteers. Renal failure has no influence on the pharmacokinetics of lansoprazole, but severe hepatic failure causes a significant decrease in clearance and an increase in the AUC and t1/2 of lansoprazole. This is accompanied by modifications in the AUC of metabolites, but severe hepatic failure has minimal effect on accumulation of the drug after multiple administration. The pharmacokinetics of lansoprazole in patients with acid-related disorders do not differ from those in healthy volunteers. Studies of interactions of lansoprazole with warfarin, prednisone, theophylline, phenazone (antipyrine), diazepam, phenytoin and oral contraceptives suggest minimal risk of any clinically significant interaction.

Lansoprazole reduces preoperative gastric fluid acidity and volume in children

The purpose of this study was to explore the efficacy of lansoprazole, a proton pump inhibitor, in reducing the acidity and volume of gastric aspirate in children immediately following the induction of anaesthesia. One hundred healthy in-patients aged 3-11 yr undergoing elective surgery were randomly allocated to four groups (n = 25 each): lansoprazole-lansoprazole, placebo-placebo, placebo-lansoprazole, and lansoprazole-placebo. For each treatment regimen, the first medication was administered at 9:00 pm on the night before surgery and the second at 5:30 am on the morning of the day of surgery (three hours preoperatively). The dose of lansoprazole was 30 mg (approximately 1.4 mg.kg-1 mean). Children were offered 10 ml.kg-1 apple juice three hours before induction of anaesthesia. After induction of anaesthesia and tracheal intubation, gastric fluid was aspirated through a large-bore, multiorifice orogastric tube and analyzed for pH and total fluid volume. Lansoprazole increased gastric fluid pH and decreased gastric fluid volume regardless of whether it was administered before or after placebo. Two consecutive doses of lansoprazole was the most effective means of increasing the pH and reducing the volume of gastric aspirate; in this group, there were no subjects with gastric aspirate volume > 0.4 ml.kg-1 and pH < 2.5. Oral lansoprazole, at least 30 mg, given on the night before surgery or on the morning of surgery will improve the gastric environment at the time of induction of paediatric anaesthesia. The most effective regimen was two doses (at bedtime and on the morning) of lansoprazole.

Pharmacological management of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) ranges from episodic symptomatic reflux without oesophagitis to severe oesophageal mucosal damage, such as Barrett's metaplasia or peptic stricture. The multifactorial pathogenesis of GORD prevents medical cure of the disease. GORD is a chronic disease with a high tendency to relapse, requiring a long term treatment strategy in practically all patients. Complete healing of all mucosal lesions is not necessarily the aim of treatment in all patients. In milder forms of reflux disease, symptom relief is the most important goal. Many patients with mild GORD do well on symptomatic self-care with antacids and/or alginate. In addition, lifestyle changes should be advised to all patients: these improve symptoms and enhance the efficacy of therapy. In the acute treatment of GORD the prokinetic drug cisapride has been shown to be effective in relieving symptoms and healing grade I to II oesophagitis. Cisapride decreases symptomatic and endoscopic relapse in patients with mild GORD. Histamine H2-receptor antagonists are effective in relieving reflux symptoms in about 50% of patients, but with regard to healing, H2-antagonists appear to be mainly effective in grades I and II and not in higher grades of oesophagitis. Maintenance treatment with H2-antagonists is mainly symptomatically effective in patients with mild GORD. Proton pump inhibitors (PPIs) provide significantly higher healing rates of reflux oesophagitis than H2-antagonists, even in the more severe cases of oesophagitis and Barrett's ulcers. PPIs are also effective in patients with oesophagitis refractory to treatment with H2-antagonists. PPIs have become the drugs of first choice in healing of all patients with more severe forms of reflux oesophagitis, and increasingly also for patients with milder forms of oesophagitis, certainly those who fail to respond to other drugs. In maintenance treatment of GORD, PPIs are the most effective drugs, offering the possibility of keeping nearly all patients in remission with adjusted doses. Current patient data of up to 5 years indicate the safety of this strategy for this period, but the exact consequences of strong acid inhibition over a longer period still have to be clarified. At present, all but a few patients with GORD can be managed adequately by medical therapy.

Lansoprazole versus ranitidine for the treatment of reflux oesophagitis. UK Lansoprazole Clinical Research Group

BACKGROUND

Lansoprazole is a H+.K(+)-ATPase (proton pump) inhibitor with an anti-secretory action and is therefore potentially useful in the treatment of gastro-oesophageal reflux.

METHODS

This study was conducted to determine the efficacy and short-term safety of lansoprazole at doses of 30 mg or 60 mg once daily, compared with ranitidine 150 mg twice daily, in the treatment of patients with reflux oesophagitis. This was a double-blind, stratified, randomized, comparative, parallel group study conducted in five centres in the UK. A total of 229 patients (155 men) aged 18-79 years with endoscopically-confirmed oesophagitis were randomized to receive lansoprazole 30 mg p.o. daily, lansoprazole 60 mg p.o. daily, or ranitidine 150 mg p.o. b.d. Efficacy was assessed by endoscopic examination at 4 weeks and 8 weeks, together with symptom relief and antacid usage.

RESULTS

Lansoprazole 30 mg and 60 mg were superior at 4 and 8 weeks (P < 0.01) to ranitidine in healing reflux oesophagitis: respective healing rates being 84%, 72% and 39% after 4 weeks and 92%, 91% and 53% after 8 weeks. Relief of heartburn with lansoprazole 30 mg and 60 mg was superior to that achieved with ranitidine at both week 4 (P < 0.01) and week 8 (P < 0.02). Sixty-four patients experienced a total of 85 adverse events, one-third of which were considered drug-related. The incidence and severity were similar in the three groups.

CONCLUSION

Lansoprazole 30 mg and 60 mg once daily are more effective than ranitidine 150 mg twice daily in the short-term treatment of reflux oesophagitis.

Treatment of erosive reflux esophagitis resistant to H2-receptor antagonist therapy. Lansoprazole, a new proton pump inhibitor

Fifty-four patients with endoscopically documented therapy-resistant erosive reflux esophagitis were treated with lansoprazole, a new proton pump inhibitor, for up to 12 weeks. Prior to entry, all had remained unhealed after treatment with at least two histamine2-receptor antagonists, at therapeutic doses or higher, for at least 12 weeks. Patients were randomized to receive either 30 or 60 mg lansoprazole once daily. Endoscopy was performed and symptoms assessed at weeks 2,4,6,8 and 12. Fifty-nine percent of the 50 evaluable patients were healed (ie, no evidence of erosions) after only two weeks of lansoprazole. Cumulative endoscopic healing rates were 82% and 92% by week 4 and week 8, respectively, and the two doses were equally effective in healing. The 30- and 60-mg doses effected a decrease in the overall symptom score from 5.30 and 4.85 to 2.35 and 1.67, respectively, by the final treatment visit (P = 0.001). No clinically significant adverse events or changes in laboratory parameters were observed, and no patients withdrew prematurely from the study. This study demonstrates that lansoprazole therapy is highly effective in healing erosive reflux esophagitis resistant to therapy with histamine H2-receptor antagonists.

Pantoprazole versus omeprazole in the treatment of acute gastric ulcers

BACKGROUND

Pantoprazole is a new substituted benzimidazole which is a potent inhibitor of gastric acid secretion by its action upon H+,K(+)-ATPase.

METHODS

The proton pump inhibitors pantoprazole and omeprazole were compared in a randomized, double-blind study in 219 patients with benign gastric ulcers. Patients received either pantoprazole 40 mg (n = 146) or omeprazole 20 mg (n = 73), once daily before breakfast for 4 weeks. Treatment was extended for a further 4 weeks if the ulcer had not healed.

RESULTS

After 4 weeks, complete ulcer healing was seen in 88% of protocol-correct patients given pantoprazole and in 77% given omeprazole (between-group difference P < 0.05). At 8 weeks, the corresponding values were 97% and 96% (not significant). In the comparative intention-to-treat analysis there were no statistical differences between the treatment groups. Among the patients who had ulcer pain prior to treatment, 79% of the pantoprazole group and 68% of the omeprazole group were pain-free after 2 weeks, and after 4 weeks 88% and 81%, respectively (not significant). Pronounced improvement in the other gastrointestinal symptoms was seen in both groups. Only 10% of patients in each group reported adverse events. There were moderate increases in fasting serum gastrin levels with both treatments at 4 and 8 weeks.

CONCLUSION

Pantoprazole, 40 mg once daily in the morning, is a highly effective, well tolerated treatment for acute, benign gastric ulcer. Pantoprazole and omeprazole were equally safe in the therapy of gastric ulcer.

Pantoprazole is superior to ranitidine in the treatment of acute gastric ulcer

BACKGROUND

Pantoprazole is a newly developed gastric H+/K(+)-adenosine triphosphatase inhibitor with a potent and long-acting inhibitory effect on gastric acid secretion.

METHODS

In a double-blind multicenter study with 28 centers in Germany, pantoprazole (40 mg before breakfast) was compared with ranitidine (300 mg at bedtime) with regard to healing rates, time until healing, symptom relief, and tolerability. A total of 248 outpatients with benign gastric ulcer were included.

RESULTS

The healing rates after 2, 4, and 8 weeks were 37%, 87%, and 97%, respectively, in the pantoprazole and 19%, 58%, and 80% in the ranitidine group. The differences between the two groups were significant at 2 weeks (p < 0.01), 4 weeks (p < 0.001), and 8 weeks (p < 0.001; Cochran/Mantel-Haenszel method). Ulcer healing proceeded significantly faster with pantoprazole (p < 0.001; Uleman's U-test). Both treatments were well tolerated.

CONCLUSIONS

Pantoprazole appears to be superior to ranitidine in gastric ulcer healing.

A comparison of lansoprazole and ranitidine in the treatment of erosive oesophagitis. Multicentre Investigational Group

BACKGROUND

Lansoprazole is a new proton pump inhibitor which produces prolonged decrease of gastric acidity. The aim of this study was to compare lansoprazole to a standard dose of ranitidine in the treatment of patients with reflux oesophagitis.

METHODS

Two hundred and forty-seven patients with erosive oesophagitis were randomly assigned to 8 weeks of treatment with either 30 mg lansoprazole once daily or 150 mg ranitidine twice daily.

RESULTS

Two hundred and forty-two patients were included in the analysis. Lansoprazole (30 mg) daily, healed oesophagitis in 92.1% of patients after 8 weeks of treatment. This was significantly superior to 150 mg ranitidine b.d.s. which healed oesophagitis in 69.9% of patients (P < 0.001). Relief of reflux symptoms was superior with lansoprazole to that with ranitidine. Both lansoprazole and ranitidine were well tolerated with no serious drug-related adverse events noted.

CONCLUSION

Lansoprazole, 30 mg once daily, is highly effective and safe in the short-term treatment of erosive oesophagitis.

Pharmacokinetic properties of a novel gastric proton pump inhibitor, (+/-)-2-[(4-methoxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9- yl)sulfinyl]-1H-benzimidazole sodium salt, in healthy subjects

The pharmacokinetics and safety of TY-11345 [(+/-)-2-[(4-methoxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9- yl)sulfinyl]-1H-benzimidazole sodium salt], a novel gastric proton pump inhibitor, were studied in healthy male volunteers after single (20, 40, and 80 mg) and repeated oral doses (60 mg, once daily for 7 days) as enteric-coated tablet. At the single doses of 20 and 40 mg, intragastric pH was continuously monitored in each of two subjects. No abnormal findings definitely attributable to the test drug were observed throughout the study. In the single-dose study, the maximum plasma concentration (Cmax) and area under the plasma concentration-time curve of TY-11345 increased in a dose-proportional manner. The time to reach Cmax was about 3 h after dosing and plasma concentrations declined thereafter with a half-life of about 1 h irrespective of dose. The effect of food intake on the pharmacokinetic parameters of TY-11345, which was evaluated at the dose of 40 mg in a cross-over design, was not significant. TY-11345 was not detected in urine unchanged, while a main metabolite and its conjugate were identified in urine as 32-38% of the dose. An intragastric pH value over 4 was obtained about 3 h after the administration of 40 mg and maintained for more than 5 h, despite the fall of plasma concentration. This effect was less obvious at a dose of 20 mg. In the multiple-dose study, the pharmacokinetics exhibited no substantial difference between the first and last doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Lansoprazole. A reappraisal of its pharmacodynamic and pharmacokinetic properties, and its therapeutic efficacy in acid-related disorders

Lansoprazole is a benzimidazole derivative that effectively decreases gastric acid secretion, regardless of the primary stimulus, via inhibition of gastric H+,K(+)-adenosine triphosphatase (ATPase). It provides effective symptom relief and healing of peptic ulcer and reflux oesophagitis after 4 to 8 weeks of therapy and appears to prevent recurrence of lesions when administered as maintenance therapy. When administered at therapeutic dosages, lansoprazole produced higher healing rates than ranitidine or famotidine in patients with duodenal and gastric ulcers. Lansoprazole heals duodenal ulcers more rapidly than ranitidine or famotidine. Relief of ulcer symptoms in lansoprazole recipients is at least equivalent to, and tends to be more rapid than, that in patients receiving histamine H2-receptor antagonists. In comparisons with omeprazole 20 mg/day, lansoprazole 30 mg/day produced duodenal ulcer healing more rapidly and reduced ulcer pain to a greater extent at 2 weeks, but overall healing rates were similar after 4 weeks of therapy. At therapeutic dosages, lansoprazole produces superior healing and symptom relief of reflux oesophagitis in comparison with ranitidine, and it tends to relieve heartburn more effectively than omeprazole, although both agents produce equivalent healing. Healing of peptic ulcers or reflux oesophagitis refractory to histamine H2-receptor antagonists occurs after 8 weeks in the majority of patients treated with lansoprazole, and lansoprazole and omeprazole demonstrate similar efficacy in patients with refractory peptic ulcers. In patients with Zollinger-Ellison syndrome, lansoprazole effectively controls mean basal gastric acid output. Lansoprazole is generally well tolerated in clinical trials. The incidence of adverse effects is similar to that of omeprazole, ranitidine and famotidine in comparative studies. Combination therapy with lansoprazole and antibacterial agents such as amoxicillin, tinidazole, roxithromycin and/or metronidazole appears to eradicate Helicobacter pylori in 22 to 80% of patients with this organism. Limited data also suggest that lansoprazole may have superior activity against H. pylori in comparison with omeprazole, although the clinical relevance of this preliminary finding requires further confirmation. Thus, lansoprazole may be considered as alternative to existing antisecretory agents available for the treatment of acid-related disorders, particularly because it may provide more rapid healing and relief of symptoms.

Review article: drug therapy for reflux oesophagitis

Gastro-oesophageal reflux disease is a common disorder and symptoms can be mild to severe. Management of the disease should be individualized. Life-style changes are important for all patients. Drug therapy is often necessary but only very few patients with severe disease need surgical treatment. The purpose of this article is to focus on drug therapy and to review the clinical trials of all the drugs used for gastro-oesophageal reflux disease. Thereafter, judged solely on the data derived from these trials, a practical approach to the management of gastro-oesophageal reflux disease is suggested.

Comparison of pantoprazole and ranitidine in the treatment of acute duodenal ulcer. Pantoprazole-Duodenal Ulcer-Study Group

BACKGROUND

Pantoprazole is a new substituted benzimidazole that blocks the H+/K(+)-ATPase in the gastric mucosa and thus inhibits acid secretion.

METHODS

Efficacy and tolerability of pantoprazole (40 mg at breakfast) and ranitidine (300 mg at bedtime) in the treatment of uncomplicated acute duodenal ulcer were compared in a double-blind randomized multicentre trial.

RESULTS

Of 202 outpatients who entered the study, 185 terminated the treatment without violation of the protocol. After 2 weeks of treatment, healing rates (protocol correct) with pantoprazole and ranitidine were 81 and 53%, respectively (P < 0.001), the corresponding results after 4 weeks were 97 and 83% (P < 0.01). Pantoprazole was more effective with respect to symptom relief. Both treatments were well tolerated.

CONCLUSION

Pantoprazole 40 mg at breakfast is superior to ranitidine 300 mg at bedtime in the short-term treatment of acute, uncomplicated duodenal ulcer.

Does lansoprazole influence postprandial digestive function?

The effects of a potent proton pump inhibitor on postprandial digestive functions were compared with those of a placebo in a double-blind randomized crossover study. Six healthy male volunteers received 30 mg/day of lansoprazole or placebo for 7 days, with a wash-out period of 14 days. As compared to placebo, lansoprazole induced a marked decrease of mean +/- S.E.M. 3-h gastric acid secretion from 46.8 +/- 10.8 mmol to 10.9 +/- 2.5 mmol (P < 0.05), and a decrease of the volume of gastric contents emptying into the duodenum from 1043 +/- 139 ml to 660 +/- 87 ml (P < 0.05). However, gastric emptying remained unchanged with meal gastric emptying half times of 66 +/- 5 min and 67 +/- 13 min, respectively. During the 3-h postprandial period, duodenal lipase and chymotrypsin outputs were 366 +/- 123 KIU and 56 +/- 11 KIU with lansoprazole and 436 +/- 119 KIU and 49 +/- 8 KIU with placebo (N.S.). Bile acid outputs were 5.3 +/- 0.7 mmol and 6.0 +/- 1.0 mmol, respectively (N.S.) There was no change in kinetic profiles of biliary-pancreatic secretion. We conclude that potent inhibition of gastric secretion by chronic administration of a proton pump inhibitor at usual therapeutic dose alters neither meal gastric emptying nor postprandial biliary-pancreatic secretion.