B

Linagliptin is eliminated mainly via the enterohepatic route (<7 % renal excretion) and pharmacokinetic studies show that its exposure is essentially unchanged across all stages of renal impairment, so no dose adjustment is required. In contrast, saxagliptin, vildagliptin and sitagliptin are predominantly cleared by the kidneys and their doses must be reduced when glomerular filtration rate falls, making them less suitable in significant renal failure [Graefe-Mody, 2011, PMID 21672124].