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Question #836

Jun 4, 2016

Continued from 835.

Mr. Fontello is an overweight, Caucasian 63-year-old patient who comes in for a 6-month check-up. He has a 12-year history of type 2 diabetes. He was diagnosed at age 33 with high blood pressure, but had never really done much about it as it was “too much of a hassle” and he felt “just fine.” At the time his diabetes was diagnosed, he was referred to a diabetes education program and was started on metformin, lovastatin, losartan and aspirin. He has an individualized A1C goal of 7%. Four years after diagnosis, pioglitazone was added to Mr. Fontello’s diabetes regimen. Three years ago, he came in for an appointment complaining of polyuria, polydipsia and fatigue with an office A1C of 9.3%. At that time, he was started nightly on basal insulin detemir. Since that time, he has made concerted efforts to eat a healthy diet and get to the gym. Today, he reports his SBGM fasting plasma glucose levels are on target (FPG<130mg/dL). He also states that his feet always feel a little bit swollen. BP 128/78, HR 73, RR 19. Physical exam is remarkable for peripheral edema and mildly decreased pedal pulses. Current medications: metformin, pioglitazone, insulin detemir, lovastatin, losartan, aspirin. At today’s visit, his office A1C is 8.1%. A rapid-acting insulin analogue was added to his largest meal of the day. Labs taken last year show Mr. Fontello had a serum creatinine 1.2mg/dL with an eGFR 61mL/min. Today, his serum creatinine is 1.6 mg/dL and his eGFR is 44 mL/min. Because guidelines indicate when a patient’s eGFR falls below 60mL/min, dose reduction of medications should be considered, you decide to adjust Mr. Fontello’s medication. In type 2 diabetes, which one of the following medications does not need to be considered for dose reduction?


Answer: D. Pioglitazon

20-30% of patients with type 2 diabetes develop moderate-severe renal disease (GFR<60mL/min). Pioglitazone does not undergo renal elimination and can therefore be used without restriction in chronic kidney disease. Metformin undergoes renal elimination and current U.S. guidelines suggest caution using in individuals with creatinine ?1.5 mg/dL (males) and creatinine ?1.4 mg/dL (females) as its use has been associated with lactic acidosis in patients with CKD. U.K. guidelines advise dose reduction of metformin at GFR of 45 ml/min and cessation with GFR of 30 ml/min. Exenatide is renally eliminated and its use should be discontinued at GFR Reference(s):

Inzucchi S, et al. Management of hyperglycemia in type 2 diabetes: A patient-centered approach. Position statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care,Jan 2015; 38(1): 140-149.