Intraluminal phosphate and bile acid anions

Intraluminal phosphate and bile acid anions are chemical species within the gastrointestinal tract that serve as targets for non-systemic binding agents to manage metabolic and electrolyte disorders. Intraluminal phosphate, derived from dietary sources, is a primary target in patients with chronic kidney disease (CKD) to prevent hyperphosphatemia and associated mineral bone disease [1]. Bile acid anions, synthesized from cholesterol in the liver and secreted into the gut to aid lipid emulsification, are targeted to lower systemic cholesterol levels or to treat diarrhea caused by bile acid malabsorption [2]. Therapeutic agents such as sevelamer, lanthanum carbonate, and cholestyramine act as sequestrants or binders, utilizing ion-exchange resins or metal salts to physically trap these anions in the gut lumen [1, 3]. This binding prevents their systemic absorption or enterohepatic recirculation, facilitating their elimination via feces [2]. Because these drugs are not absorbed into the bloodstream, they primarily cause localized gastrointestinal side effects and may interfere with the absorption of other medications and fat-soluble vitamins [1, 2].

Other names

Dietary phosphateIntestinal bile acidsFecal anionsLuminal phosphate

Physical sequestration and ion exchange within the gastrointestinal lumen to inhibit systemic absorption or enterohepatic circulation.