Gastric emptying of two radiolabelled antacids with simultaneous monitoring of gastric pH.
The aim of this study was to assess the gastric emptying rate of two antacids using an scintigraphic technique and simultaneous monitoring of gastric pH in 16 healthy male volunteers. Ten ml of Talcid (hydrotalcite 1 g) and Maalox (Mg-Al-hydroxide), with a similar neutralization capacity, were labelled with technetium-99m using a pyrophosphate bridge. Labelled antacids were given on separate days (within 2 weeks), 1 h after a standard meal. Intragastric pH was measured for at least 4 h, using ambulatory pH-metry with a dual-crystant antimony catheter. Continuous monitoring was started 1 h prior to the meal (baseline) and lasted 3 h (post-prandial, post-antacid and final periods). The antacid capacity of labelled and unlabelled antacids was similar. The mean percentages of antacids retained in the stomach fitted a linear model. The mean half-emptying time of Talcid was 63.9 +/- 27.9 min, while that of Maalox was 57.3 +/- 23.9 min (P = NS). The recordings of gastric pH (mean values of pH for each period) showed a similar profile for both antacids. The mean pH (Maalox vs Talcid) was 1.69 vs 2.07 in the baseline period, 1.95 vs 1.93 in the post-prandial period, 1.79 vs 1.15 in the post-antacid period (P = NS) and 0.4 vs 0.52 in the final period (P < 0.05 vs prior periods). In conclusion, the gastric emptying of Talcid and Maalox was similar and pH profiles were parallel and remained unchanged for the two antacids within the first hour of intake. A significant decrease in pH was observed 1 h after intake of the antacids, suggesting a possible rebound effect.
Servicio de Patologia Digestiva, Hospital de la Sante Crei i Sant Pau, Universitat Autónoma Barcelona, Spain.
J
J
Monés
I
I
Carrio
S
S
Sainz
L
L
Berná
P
P
Clavé
M
M
Liszkay
M
M
Roca
F
F
Vilardell
D000328:Adult; D000536:Aluminum Hydroxide / Q000493:pharmacokinetics / Q000494:pharmacology; D000863:Antacids / Q000493:pharmacokinetics / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004338:Drug Combinations; D005745:Gastric Acidity Determination; D005746:Gastric Emptying; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008276:Magnesium Hydroxide / Q000493:pharmacokinetics / Q000494:pharmacology; D008297:Male; D016698:Technetium Tc 99m Pyrophosphate
D000863:Antacids; D004338:Drug Combinations; C010467:hydrotalcite; C013591:aluminum hydroxide, magnesium hydroxide, drug combination; D016698:Technetium Tc 99m Pyrophosphate; D000536:Aluminum Hydroxide; D008276:Magnesium Hydroxide