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.