Bariatric surgery and oral drug absorption
Theoretically, as a result of bariatric surgery, a number of alterations in the process of oral drug absorption may be expected which may alter the oral pharmacokinetic profiles of prescribed drugs. Table 1 summarizes these alterations, for which a distinction is made between changes occurring upon restrictive procedures, i.e. procedures leading to a limitation in the amount of food in the stomach such as adjustable gastric banding and gastroplasty, or to limited digestive capacity such as SG, versus combined restrictive/malabsorptive procedures that also cause malabsorption of nutrients, such as Roux-en-Y gastric bypass (RYGB). Whether or not these changes ultimately lead to altered pharmacokinetics of a specific drug will depend on individual drug properties. Here we discuss disintegration of the oral drug formulation, dissolution of the drug, gastrointestinal transit time and the role of bile acids as factors of interest for the absorption process of oral drugs.