Population pharmacokinetics of glyburide in patients with well-controlled diabetes.
STUDY OBJECTIVES: To investigate glyburide pharmacokinetics in patients with well-controlled noninsulin-dependent diabetes mellitus (NIDDM), and test the hypothesis that intersubject variability in the glyburide dose is due to patient differences in the drug's pharmacokinetics. METHODS: Prospective, open-label study. SETTING: University-affiliated, internal medicine outpatient clinic. PATIENTS: Fifty-one patients with NIDDM (11 women, 40 men, mean age 56.7 +/- 15.3 yrs) receiving oral glyburide and with well-controlled glycohemoglobin levels 10.0% or below. INTERVENTION: After fasting overnight, patients ingested their regular morning dose of glyburide and then ate breakfast. Blood samples were drawn before dosing and between 0.5-2 hours, 2-5 hours, and 5-10 hours after dosing. MEASUREMENTS AND MAIN RESULTS: Serum glyburide was assayed by high-performance liquid chromatography and pharmacokinetics by NONMEM. Glyburide clearance was proportional to weight and greater in older patients (> 60 yrs). CONCLUSION: Variability in the glyburide dose was not primarily due to intersubject differences in the drug's pharmacokinetics.