Pharmacokinetics of glyburide.

The pharmacokinetics of glyburide can be described by a two-compartment open model. Terminal-phase descriptions are formulation-dependent and are complicated by apparent food-associated mobilization of drug from the stomach. Some researchers indicate a possible third (or deep) compartment, but this appears to be an artifact of a nonspecific drug assay. Although no accumulation has been observed in short-term studies, further investigation of the possibility of drug accumulation with long-term therapy is needed. Distribution of glyburide is affected by high affinity for serum albumin (99 percent bound), and elimination of the drug appears to be evenly divided between biliary and renal routes. The biologic half-life of glyburide is not significantly correlated with renal function in subjects with creatinine clearances of 30 ml/minute/1.7 m2 or more. Gradations in disease state, multiple sites of sulfonylurea action, and inter-patient variability have made it difficult to relate biologic response to glyburide serum levels.