A study was conducted to compare the efficacy of ranitidine and nizatidine for prophylaxis of acid aspiration in 30 healthy, ASA 1 patients, undergoing elective surgery.

This double-blind study randomized randomized the patients to receive either ranitidine 300 mg, nizatidine 300 mg or placebo (10 patients in every group). Patients fasted for a minimum of 8 hours before induction of anesthesia. Gastric volume and pH were measured in all patients.

• Ranitidine and nizatidine were found to have similar efficacy in reducing gastric volume and increasing gastric pH (Table).
• Not even a single patient was at risk of acid aspiration following pretreatment with either of the two drugs.

The study concluded that ranitidine and nizatidine are similarly very effective in reducing gastric pH and volume.

Table. Effect of ranitidine and nizatidine on gastric pH and volume

Source: Moote CA, McAllister J, Sharpe MD, et al. Random double blind comparison of ranitidine, nizatidine and placebo in reducing gastric acidity. Anesth Analg. 1990;70(2):S274.