Cimetidine as an oral antacid before elective Caesarean section.

The H2-receptor antagonist cimetidine was used as a pre-operative antacid in 64 women scheduled for elective Caesarean section. All were given cimetidine 400 mg 90-215 minutes before induction, with 20 of them having an extra 400 mg dose the previous night. The intragastric pH at induction of anaesthesia was reliably above 2.5 if the treatment was given 90-150 minutes beforehand. The volume of gastric contents was reduced when compared with a control series of women receiving either no pre-operative antacid or 30 ml magnesium trisilicate mixture BPC. No adverse effects on mothers or infants were detected.