“…64 Cimetidine and ranitidine administered orally or by infusion do not alter LES pressures 67'68 but, when used in appropriate dosage and with proper timing, their effectiveness in reducing gastric volume and increasing pH cannot be denied. For example, the combination of oral cimetidine, 300 mg, administered the night before surgery plus 300 mg of intramuscular cimetidine administered 60 to 90 minutes before induction increased gastric pH to 5.0 in all the patients studied by Weber and Hirshman.69 For a detailed review of cimetidine and newer H~-receptor antagonists as they relate to anaesthesia, the reader is referred to the article by Manchikanti et al 7~ The net effect on gastroesophageal reflux and subsequent pulmonary aspiration should therefore be beneficial, but studies demonstrating the correctness of this statement have yet to be published.…”