Сукральфат

Описание

Sucralfate is a complex of the sulfuric acid ester of sucrose and aluminum hydroxide. Secondary polymerization with aluminum hydroxide forms intermolecular bridges between molecules of sulfate esters with aluminum. Limited dissociation of the complex occurs in gastric acid, but these anionic sulfate esters form insoluble adherent complexes with the proteinaceous exudate at the abraded surface of a crater of the ulcerated area in the stomach. This physical complex protects the ulcer from the erosive action of pepsin and bile salts. Sucralfate also stimulates synthesis and release of prostaglandins, bicarbonate, and epidermal and fibroblast growth factors. Significant ulcer healing effects are noted in placebo-controlled trials. Only small amounts of sucralfate are absorbed systemically. In renal impairment, there is a risk of accumulation of absorbed aluminum from the drug. Sucralfate reduces absorption of other drugs, including H2 antihistamines, quinolone antibiotics, phenytoin, and perhaps, warfarin

Химические свойства

White Powder

Использование

Sucralfate, an aluminum salt of sucrose octasulfate, is used as an antacid and antiulcer medication. Bis- and tris-platinum complexes of sucrose show promise as antitumor agents. Sucrose monoesters are used in some pharmaceutical preparations.

Показания

Sucralfate (Carafate) is an aluminum hydroxide–sulfated sucrose complex that is only minimally absorbed from the GI tract. After exposure to gastric acid, the compound becomes negatively charged, creating a viscous adherent complex. This complex is believed to inhibit back-diffusion of H .Other effects are a direct reduction in pepsin activity and a slight rise in tissue prostaglandin levels. Stimulation of a cytoprotection mechanism may therefore assist mucosal healing. The drug has no acid-buffering capacity.

Общее описание

Sucralfate, 3,4,5,6-tetra-(polyhydroxyaluminum)-α-D-glucopyranosyl sulfate-2,3,4,5-tetra-(polyhydroxyaluminum)-β-D-fructofuranoside sulfate (Carafate), isthe aluminum hydroxide complex of the octasulfate ester ofsucrose. It is practically insoluble in water and soluble instrong acids and bases. It has a pKa value between 0.43 and1.19.
Sucralfate is minimally absorbed from the GI tract by design,and thus exerts its antiulcer effect through local ratherthan systemic action. It has negligible acid-neutralizing orbuffering capacity in therapeutic doses. Although its mechanismof action has not been established, studies suggestthat sucralfate binds preferentially to the ulcer site to form aprotective barrier that prevents exposure of the lesion to acidand pepsin. In addition, it adsorbs pepsin and bile salts.Either would be very desirable modes of action.
The simultaneous administration of sucralfate may reducethe bioavailability of certain agents (e.g., tetracycline, phenytoin,digoxin, or cimetidine). It further recommends restorationof bioavailability by separating administration of theseagents from that of sucralfate by 2 hours. Presumably, sucralfatebinds these agents in the GI tract. The most frequentlyreported adverse reaction to sucralfate is constipation (2.2%).Antacids may be prescribed as needed but should not be takenwithin 0.5 hour before or after sucralfate.

Клиническое использование

Sucralfate is frequently used for prophylaxis of stress-induced gastritis in patients in intensive care units. It has also been successfully used in small numbers of patients as a suspension enema to treat radiation proctitis.