With the predicted epidemic of type 2 diabetes mellitus and the clear link between glycemic control and longterm outcomes, the use of oral hypoglycemic agents is likely to increase. The major adverse effect of sulfonylurea agents is hypoglycemia, which traditionally is treated with hypertonic dextrose. Our case illustrates the challenges and pitfalls of the management of relapsing hypoglycemia in a hemodialysis patient on regular gliclazide.
Case ReportA 47-year old hemodialysis patient with type 2 diabetes mellitus was admitted to the hospital because of vascular access problems. He usually took 80 mg of gliclazide once a day, with a capillary blood glucose measurement (BM) of 6-10 mmol/L. Other medications that he took included omeprazole, amlodipine, fluoxetine, ramipril, amitriptyline, atorvastatin, aspirin, and darbepoetin alfa.One week into his admission, the patient became septic and was started on empirical treatment with vancomycin for a presumed catheter-related infection. During the night, his BM gradually fell to 1.9 mmol/L despite regular snacks. In the morning he was confused, hypotensive, and sweating profusely. He was resuscitated with 50 mL of 50% dextrose given intravenously (IV), 1 mg of glucagon given subcutaneously (SC), and IV fluids.His condition improved temporarily. However, during the course of the day, he had 4 additional episodes of symptomatic hypoglycemia requiring intervention with boluses of 50% dextrose. A second dose of glucagon was given, mainly in an attempt to reduce the amount of IV dextrose necessary (Figure 1). A clear decrease in the response to hypertonic dextrose was noted, both in peak BM attained and in the time before a repeat bolus was needed. On the fifth occasion, his BM fell to 2.2 mmol/L, and he was given a single dose of 50 g of octreotide SC in addition to 50 mL of 50% dextrose IV and 100 mg of hydrocortisone IV. Within 20 minutes his BM was 8.6 mmol/L, and it remained above 5.5 mmol/L for the next 6 hours. Subsequent BMs ranged from 10 to 14 mmol/L.His serum cortisol level measured at 4 PM, prior to administration of hydrocortisone, was 501 nmol/L (9 AM reference range 120-500 nmol/L), with an insulin level of 1098 pmol/L (normal range 0-75 pmol/L). Blood cultures yielded methicillin-sensitive Staphylococcus aureus. His dialysis catheter was removed, and gliclazide was permanently discontinued. He had no further episodes of hypoglycemia and made a full recovery.
DiscussionSulfonylureas act predominately by stimulating the release of preformed insulin from pancreatic -cells. They also enhance insulin activity by reducing extrahepatic clearance of insulin. Sulfonylureas are hepatically metabolized and differ predominately in their duration of action and in the degree of renal excretion of the parent compound or active metabolite. In the UKPDS study, the incidence of major sulfonylurea-associated hypoglycemia was 1.0%-1.4%, compared with an incidence of 1.8% with insulin. 1 In general, this risk is increased in older patients; with renal impairment, liver disea...