(2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine

Absorption
Sitagliptin is rapidly absorbed, with 100 mg reaching a C max of 950 nM in 1 to 4 h. The bioavailability is approximately 87%.

Distribution
Vd is approximately 198 L. Plasma protein binding is 38%.

Metabolism
Metabolism by CYP3A4 and, to a lesser degree, CYP2C8 is a minor pathway in the Cl of sitagliptin.

Elimination
Terminal t ½ is approximately 12.4 h. Approximately 13% is excreted in feces and 87% in urine via active tubular secretion (79% as unchanged drug). Sitagliptin is a substrate for organic anion transport.

Cyclosporine
Sitagliptin plasma concentrations may be increased modestly (approximately 68%), which is not expected to be clinically important.

Digoxin
Digoxin plasma levels may be increased slightly (approximately 18%); no dosage adjustment is recommended.