Influence of several surgical techniques in peptic ulcer disease on the oral kinetic of a basic drug

Abstract

The effect of gastric surgery on the absorption of a basic drug propranolol was studied in 11 patients. 80 mg of propranolol were administered orally before and after surgery. Irrespective of the surgical technique, there was only a significant decrease in the absorption constant Ka (1.10 +/- 0.14 vs 0.72 +/- 0.09) (p < 0.05), indicating a delay in the gastrointestinal absorption, which agreed with the delay in the urine excretion in the first six hours after surgery (6.8 +/- 0.8 vs 1.7 +/- 0.4) (p < 0.001). Patients with vagotomy but without gastric resection showed a significant increase in the time of attainment of peak concentration tmax (2.4 +/- 0.2 vs 3.2 +/- 0.3), and decrease in Ka (1.5 +/- 0.12 vs 0.73 +/- 0.17) (p < 0.05), indicating also a delay in the gastrointestinal absorption, that is not seen in patients with partial gastric resection. We conclude that vagotomy with gastric resection does not modify the absorption of propranolol, and vagotomy without resection delays its absorption but does not decrease it.