Association between use of warfarin with common sulfonylureas and serious hypoglycemic events: Retrospective cohort analysis

Abstract

Study question Is warfarin use associated with an increased risk of serious hypoglycemic events among older people treated with the sulfonylureas glipizide and glimepiride? Methods This was a retrospective cohort analysis of pharmacy and medical claims from a 20% random sample of Medicare fee for service beneficiaries aged 65 years or older. It included 465 918 beneficiaries with diabetes who filled a prescription for glipizide or glimepiride between 2006 and 2011 (4 355 418 person quarters); 71 895 (15.4%) patients also filled a prescription for warfarin (416 479 person quarters with warfarin use). The main outcome measure was emergency department visit or hospital admission with a primary diagnosis of hypoglycemia in person quarters with concurrent fills of warfarin and glipizide/glimepiride compared with the rates in quarters with glipizide/ glimepiride fills only, Multivariable logistic regression was used to adjust for individual characteristics. Secondary outcomes included fall related fracture and altered consciousness/mental status.