title: Ranitidine suspension or famotidine resoriblette and gastric fluid volume and pH.
abstract: We studied the effect of two new formulations of H2-receptor antagonists on gastric fluid pH and volume. Forty-five healthy, elective adult in-patients in three study groups, 15 in each, were premedicated using oral diazepam 10 mg with 100 ml of a dose of water soluble suspension of ranitidine 300 mg with sodium citrate/bicarbonate, or a resoriblette of famotidine 40 mg, or placebo. Gastric fluid samples were obtained by blind aspiration after anaesthesia induction, 50-70 min from premedication, and again 90 min from premedication. After a mean period of 60 min from ingestion the patients medicated with H2-antagonists had higher gastric juice pH than those in the control group (1.5 (1.1-6.3), median (range)) (P < 0.0001) for ranitidine (6.8 (4.1-7.8)), P < 0.01 for famotidine (3.9 (1.5-7.6)); P < 0.05 ranitidine vs famotidine). Recovered volumes were similar for the groups (median 3-4 ml, range 0-50 ml). None of the H2 patients had pH < 3.5 and volume > or = 0.3 ml.kg-1 (P < 0.05 vs placebo). In second aspirations, taken 90 min from premedication, the group differences from control in pH persisted. Famotidine patients had the lowest volumes (P < 0.05 vs controls); yet one famotidine patient had a pH < 2.5 and volume > or = 0.3 ml.kg-1. It is concluded that, at the moment of oral anxiolytic premedication, ranitidine-buffer suspension effectively reduced gastric juice acidity, whereas famotidine resoriblette failed to increase reliably gastric pH in 50-90 min.
mesh_terms: D000293:Adolescent; D000328:Adult; D015738:Famotidine / Q000008:administration & dosage*; D005260:Female; D005745:Gastric Acidity Determination; D006635:Histamine H2 Antagonists / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000517:prevention & control; D011292:Premedication; D011899:Ranitidine / Q000008:administration & dosage*; D013270:Stomach / Q000187:drug effects*; D013535:Suspensions
chemical_list: D006635:Histamine H2 Antagonists; D013535:Suspensions; D015738:Famotidine; D011899:Ranitidine