PT - JOURNAL ARTICLE AU - ARYEH HURWITZ TI - THE EFFECTS OF ANTACIDS ON GASTROINTESTINAL DRUG ABSORPTION. II. EFFECT ON SULFADIAZINE AND QUININE DP - 1971 Dec 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 485--489 VI - 179 IP - 3 4099 - http://jpet.aspetjournals.org/content/179/3/485.short 4100 - http://jpet.aspetjournals.org/content/179/3/485.full SO - J Pharmacol Exp Ther1971 Dec 01; 179 AB - Magnesium- and aluminum-containing preparations were given to rats by gastric intubation to study the effects of these agents on the gastrointestinal absorption of sulfadiazine, a weak acid, and quinine, a weak base. Sodium sulfadiazine absorption is transiently and slightly depressed by magnesium hydroxide or atropine pretreatment. Sulfadiazine blood levels were much lower in animals who received either aluminum hydroxide or aluminum chloride before sodium sulfadiazine. In contrast, the gastrointestinal absorption of sulfadiazine acid was increased by magnesium hydroxide gel, which raises gastric pH sufficiently to increase the water solubiity of this drug, whereas aluminum hydroxide gel has no effect on sulfadiazineacid absorption. Both magnesium hydroxide and aluminum hydroxide depress gastrointestinal quinine absorption, the former by raising the pH sufficiently to precipitate the quinine and the latter primarily by retarding gastric emptying. © 1971 by The Willams & Wilkins Co.