Glimepiride
Glimepiride. Third-generation sulfonylurea — same K-ATP β-cell mechanism but lower hypoglycemia rate than glyburide. CYP2C9 substrate.… Oral half-life 2.4 h.
Third-generation sulfonylurea — same K-ATP β-cell mechanism but lower hypoglycemia rate than glyburide. CYP2C9 substrate. Once-daily dosing.
PK: AN INTRAVENOUS VOLUME MARRIED TO AN ORAL TERMINAL HALF-LIFE, AND THE FEASIBILITY TEST IS DECISIVE. The half-life is verbatim and is a stated mean, but pairing it with the label volume asserts a clearance of 12.4 mL/min against a verbatim "Mean relative total clearance and mean volume of distribution of both single ... (41.6 ml/ min and 8.47 litres, respectively, when creatinine clearance was above 50 ml/min)" — AND THAT VERBATIM PAIR ITSELF IMPLIES A HALF-LIFE OF 2.35 h, NOT 8.2. The record own citation agrees independently. THE HARD PART IS THAT NO RESCALING FIXES IT: its exposure-to-peak ratio of 4.05 h sits against a floor of 11.83 h at the stored half-life, and reaching that floor would require two thirds of all exposure to arrive beyond twenty-four hours, which is impossible over fewer than three half-lives. As stored the model renders the peak 43% LOW while exposure is twice HIGH — errors in opposite directions, so no change to volume or bioavailability can satisfy both. The half-life moves and the volume stays. THE BIOAVAILABILITY IS RIGHT AND MUST NOT BE TOUCHED: "The tablet formulation of glimepiride is completely bioavailable." CAVEAT AGAINST MYSELF: the replacement cohort is diabetics with mild renal impairment, not healthy volunteers, but the record own citation corroborates both direction and magnitude.
Pharmacokinetics
- Oral — t½ 2.4 h · F 100% · Vd 8.8 L
Sources: PMID:20110017, PMID:8960852, PMID:12369756