Sodium-glucose co-transporter 2 (SGLT2), expressed in the proximal renal tubules, is responsible for the majority of the reabsorption of filtered glucose from the tubular lumen. Canagliflozin is an inhibitor of SGLT2. By inhibiting SGLT2, canagliflozin reduces reabsorption of filtered glucose and lowers the renal threshold for glucose (RTG), and thereby increases urinary glucose excretion.
Canagliflozin binds to SGLT2 more potently (250-times) than SGLT1 in vitro. The 50% inhibitory concentrations (IC50) are 2.2-4.4 nmol/L and 684 - 910 nmol/L for SGLT2 and SGLT1 respectively. Dose dependent decreases in renal threshold for glucose and increases in urinary glucose excretion were observed when single and multiple oral doses were administered to type 2 diabetes patients. Decreases in plasma glucose in a dose-dependent fashion were also noted as early as the first day of administration. When given to healthy and type 2 diabetic patients before a meal, a delay in intestinal glucose absorption and a reduction in postprandial glucose was observed. Canagliflozin does not prolong the QTc interval.
Canagliflozin is hepatically metabolized via O-glucuronidation into two inactive O-glucuronide metabolites. The enzymes that facilitate this process are UGT1A9 and UGT2B4. To a lesser extent (7%), canagliflozin also undergoes oxidative metabolism via CYP3A4. Canagliflozin weakly inhibited CYP2B6, CYP2C8, CYP2C9, and CYP3A4 based on in vitro studies with human hepatic microsomes.
Most common adverse reactions associated with canagliflozin (5% or greater incidence): female genital mycotic infections, urinary tract infection, and increased urination.
Lamos EM, Younk LM, Davis SN: Canagliflozin , an inhibitor of sodium-glucose cotransporter 2, for the treatment of type 2 diabetes mellitus. Expert Opin Drug Metab Toxicol. 2013 Jun;9(6):763-75. doi: 10.1517/17425255.2013.791282. Epub 2013 Apr 17. Pubmed