THE EFFECT OF OMEPRAZOLE ON LIQUID GASTRIC-EMPTYING IN NORMAL VOLUNTEERS

The present study was designed to investigate the influence of omepraz ole-induced hypochlorhydria on gastric emptying. Six healthy male volu nteers participated in a cross over randomised study and on one of the two occasions were pretreated with 240 mg omeprazole administered in three divided doses over the 22 h preceding the test. Gastric emptying after the various regimens was calculated from the paracetamol data b y the proportional cumulative AUC method (PCAUC) i.e. the amount of pa racetamol absorbed at the various time intervals with and without pret reatment expressed as a proportion of the total amount of paracetamol alone, absorbed over 2 h. A decrease in the PCAUC represents a delay i n liquid gastric emptying. Omeprazole pretreatment selectively inhibit s H+, K+-ATPase and the pH of the volunteer's gastric secretions rose from a median of 2.8 to 8.0. The basal acid output (BAO) decreased fro m a median of 0.14 mmol . h(-1) to 1.01 x 10(-6) mmol . k(-1). Omepraz ole pretreatment significantly (p<0.05) delayed gastric emptying at 15 , 30 and 45 min, the respective PCAUC's median values were 0.01, 0.10 and 0.28, while the corresponding values with normochlorhydria were, r espectively, 0.08, 0.28 and 0.43.