The Effect of Omeprazole on Serum Concentrations of Theophylline, Pepsinogens A and C, and Gastrin in Elderly Duodenal Ulcer Patients.

With the aim of verifying the effect of omeprazole treatment on theophyline serum concentration in elderly peptic ulcer patients, we studied 10 male subjects aged >65 years (mean age = 75.2, range = 67--86) with chronic obstructive bronchopneumonia and endoscopically diagnosed duodenal ulcer in acute phase. All subjects were treated with a slow-release formulation of theophylline 200 mg b.i.d. plus omeprazole 20 mg daily for 4 weeks. In all subjects serum concentrations of azote, creatinine, theophylline were determined at the beginning and after 1 and 4 weeks; at the beginning and end of the study, pepsinogen group A (PGA), pepsinogen group C(PGC) and gastrin were measured. Statistical analysis was performed with the Student's t-test for paired data. The results showed no statistically significant differences after 1 and 4 weeks of omeprazole treatment in serum concentrations of theophylline (T(0) = 7.4, T(1 week) = 7.5, T(4 weeks) = 6.0, p = ns), azote (T(0) = 45.2, T(1 week) = 30.5, T(4 weeks) = 36.1, p = ns), creatinine (T(0) = 1.27, T(1 week) = 1.02, T(4 weeks) = 1.16, p = ns), PGA (T(0) = 99.5, T(4 weeks) = 126.2, p = ns), and PGC (T(0) = 10.6, T(4 weeks) = 12.1, p = ns); however serum gastrin increased from T(0) = 70.2 plus minus 13.2 to T(4 weeks) = 130.3 plus minus 18.3 (p < 0.0001). It was concluded that (1) serum concentration of theophylline is not affected by the concomitant omeprazole treatment lasting 1 month in elderly patients suffering from chronic obstructive bronchopneumonia and peptic ulcer, (2) modifications of dosages of theophylline and/or omeprazole are not necessary in the elderly with normal renal function, (3) the increase in fasting serum gastrin after 4 weeks of treatment may indicate that omeprazole 20 mg daily is efficacious in inhibiting gastric acid secretion in the elderly people.