Digestive Diseases and Sciences, Vol. 30, No. 1 (January 1985), pp. 45-51 Factors Influencing Healing of Duodenal Ulcer Control of Nocturnal Secretion by Characteristics of Patients who H2 Blockade and Failed to Heal SHIU-KUM LAM, CHING-LUNG LAI, LOUIS N.W. LEE, KAI-HING FOK, MATHEW M.T. NG, and KIN-FUN SIU To study the efficacy of a single bedtime dose of H2-receptor antagonist in the healing of duodenal ulcer, a 12-week randomized double-blind controlled trial of oxmetidine, which is equipotent to cimetidine and has a similar duration of action, was performed in 80 patients. Oxmetidine, 600 mg bedtime, resulted in significantly more complete healing than placebo at weeks 2, 4, 6, 8, 10, and 12 as assessed endoscopically. At weeks 4 and 6, 72.5% and 85%, respectively, of ulcers were completely healed by oxmetidine, and 36.8% and 41.7%, respectively, by placebo. 0f45 prospectively obtained patient characteristics, high pentagastrin-stimulated maximal acid output and large ulcer diameter significantly affected healing adversely. These results indicate that duodenal ulcer healing may be achieved by reducing the nocturnal acid secretion alone. Reduction of nocturnal gastric acid secretion using He-receptor antagonists prevents recurrence of du- odenal ulcer (1). Whether reduction of nocturnal acid secretion is associated with healing of duode- nal ulcer is unknown. Oxmetidine is an He-receptor antagonist containing an imidazole ring and an isocytosine moiety. Weight for weight, it is two to four times as potent as cimetidine when given intravenously, and equipotent when given orally; its duration of action is similar to that of cimetidine (2). Manuscript received March 29, 1984; revised manuscript received August 7, 1984; accepted August 16, 1984. From the Combined Gastrointestinal Unit, Departments of Medicine and Surgery, University of Hong Kong Queen Mary Hospital, Hong Kong. Part of work presented at AmericanGastroenterological Asso- ciation Annual Meeting, May 23-25, 1983, Washington D.C. Supported by University Research Grants (041.0006, 041.0009) and Wing Lung Bank MedicalResearch Fund (311/030/8009/31), University of Hong Kong. Address for reprint requests: Dr. S.K. Lam, Department of Medicine, University of Hong Kong, Queen Mary Hospital. We have conducted a 12-week double-blind con- trolled trial to study the effect of a bedtime dose of oxmetidine on the healing of duodenal ulcer. Our results show for the first time that a single bedtime dose of H2 antagonist is more effective than placebo and thus strongly imply that by reducing the noctur- nal acid secretion alone, significant healing of duo- denal ulcer can be achieved. MATERIALS AND METHODS Patients. Candidates were recruited from patients at- tending the University Medical and Surgical Gastrointes- tinal Clinics as well as patients admitted to the general medical, surgical and gastrointestinal wards of the Uni- versity Departments of Medicine and Surgery, Queen Mary Hospital, Hong Kong. This has the advantage of including a wide spectrum of patients into the study. Candidates were excluded from consideration if they had a concomitant medical problem, particularly renal dis- ease, cardiovascular disease, diabetes meUitus, or chron- ic obstructive airways; pyloric stenosis; previous gastric operations for ulcer; or an associated gastric ulcer. In- formed consent was obtained from each patient. The Digestive Diseases and Sciences, Vol. 30, No. 1 (January 1985) 0163-2116/85/01004)045504.50/0 9 1985 Plenum Publishing Corporation 45