six asymptomatic , non-smoking men with endoscopically proven duodenal ulcer disease received single nocturnal doses of placebo , 40 mg famotidine and 300 mg ranitidine each for 1 week prior to serial measurement of ph , peptic activity and serum gastrin concentrations over 24 h and of acid output .
C0013295
duodenal ulcer
C0034665
ranitidine