title: The assessment of gastric acidity and antacid effect in pregnant women by a non-invasive radiotelemetry technique.
abstract: Non-invasive radiotelemetry techniques were used for the in-vivo assessment of gastric acidity and the effect of antacids in non-pregnant women and women in the third trimester of pregnancy. A particulate (magnesium trisilicate mixture) and a non-particulate (sodium citrate) antacid were studied. There was no significant difference in basal gastric acidity and gut transit time between the pregnant and non-pregnant subjects. The median and range of values for the efficacy (defined as the integrated area under the pH/time curves) of sodium citrate was 138.3 pH.min (29.8-520.7) in the non-pregnant and 103.0 pH.min (54.3-375.6) in the pregnant subjects. The median and range of values for the duration of action of sodium citrate were 38.6 (18.1-147.4) min in the non-pregnant and 30.5 (20.0-119.1) min in the pregnant women. Magnesium trisilicate mixture resulted in a greater intragastric pH change and had a greater efficacy than sodium citrate, but the duration of action of the two antacids was similar.
mesh_terms: D000328:Adult; D000863:Antacids / Q000494:pharmacology*; D002951:Citrates / Q000494:pharmacology*; D019343:Citric Acid; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology*; D017633:Magnesium Silicates; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012824:Silicic Acid / Q000494:pharmacology*; D012822:Silicon Dioxide / Q000494:pharmacology*; D013607:Tablets; D013686:Telemetry
chemical_list: D000863:Antacids; D002951:Citrates; D017633:Magnesium Silicates; D013607:Tablets; D012824:Silicic Acid; D019343:Citric Acid; D012822:Silicon Dioxide; C001671:magnesium trisilicate; D008274:Magnesium