Nocturnal intragastric acidity after over‐the‐counter doses of famotidine, ranitidine or placebo

Abstract

Aim: To compare the inhibitory effects of over‐the‐counter doses of famotidine or ranitidine on nocturnal intragastric acidity in a placebo‐controlled study. Methods: Twelve‐hour intragastric acidity was measured simultaneously in 24 healthy subjects who ate a standard meal at 18.30 h and were dosed (at 19.30 h) with either famotidine 10 mg, ranitidine 75 mg or placebo in a balanced three‐period crossover design. Five‐millilitre aliquots of gastric juice were aspirated half‐hourly 0–3 h post‐dose, and then hourly until the end of the study. pH was measured with a glass electrode. Integrated pH (area under the curve (AUC) of the pH–time curve) was calculated for the intervals 0–12 h and 9–12 h post‐dose. Statistical analysis was by ANOVA. Results: In the 0–12 h post‐dose period, when the 24 subjects were dosed with placebo, mean AUC was 2.12, dosed increasing by 75% to 3.70 with famotidine (P < 0.001) and by 81% to 3.83 with ranitidine (P < 0.001). In the 9–12 h post‐dose period, when the subjects were dosed with placebo, mean AUC was 2.13 increasing by 91% to 4.07 with famotidine (P < 0.001) and by 79% to 3.82 with ranitidine (P < 0.001). There was no significant difference between the pH‐raising effects of famotidine and ranitidine in both periods. Conclusions: Famotidine and ranitidine in over‐the‐counter doses have a similar, sustained, effect on post‐prandial nocturnal intragastric acidity in healthy subjects lasting up to 12 h after oral dosing.

Control of intragastric acidity with over‐the‐counter doses of ranitidine or famotidine

“…In this study, the gastric acid inhibitory effect of ranitidine, 75 mg, and famotidine, 10 mg, taken around midday, persisted even in the overnight period. Overall, the effects of ranitidine and famotidine were similar and consistent with previous studies which have evaluated low doses of famotidine and ranitidine 3–6 , . 16 However, it is uncertain whether this late and modest effect can translate into symptomatic benefit for patients.…”

“…Several studies have compared the onset and duration of action of ranitidine, famotidine and cimetidine on intragastric acidity using the model of 24‐h acidity 3–6 . This model was designed for the study of the effect of these drugs on gastric acidity by attempting to simulate normal everyday activity.…”

Impact of food intake on the antisecretory effect of low‐dose ranitidine and famotidine

“…30 In this situation, taking the H 2 -antagonist after the last meal is recommended. Grimley et al 10 found no signi®cant difference in the ef®cacy of these drugs on nocturnal intragastric acidity.…”

“…Studies comparing the efficacy of the H 2 ‐antagonists at over‐the‐counter dosage were usually performed either in fasting or postprandial subjects 6 –11 . It is well known that meal intake reduces the acid inhibitory effect of high dose H 2 ‐antagonists 12 –14 .…”

Acid peptic diseases: pharmacological approach to treatment

“…Over-the-counter H2RAs doses (ranitidine 75 mg, famotidine 10 mg), are less than those listed in the prescription product insert, however, at these doses they are effective in reducing overnight gastric acidity for 12 h [61], as well as blunting the food-stimulated gastric response [62,63]. They are also effective in the treatment of symptomatic GERD [47].…”