AVOIDING DRUG-INDUCED HYPOGLYCEMIA

Pharmacists can forewarn patients of possible excessive blood sugar lowering by checking patient profiles and by applying the appropriate warning stickers to medication containers.

alcohol is to be ingested, they should use moderation and take the drink with food.

Salicylates: Serum glucose-lowering action of insulin may be intensified because salicylates increase basal insulin concentrations and the acute insulin response to glucose load is enhanced. In the event the patient begins to use aspirin, either for an acute event, such as a fever, or a chronic condition, such as arthritis, they should monitor blood glucose concentrations and tailor insulin regimens as needed.

Sulfonylurea Drug Interactions

Beta-blockers: These drugs can attenuate the hypoglycemic effects of sulfonylureas. To manage patients on beta-blockers, physicians or pharmacists must closely monitor blood glucose levels and watch for clinical signs of hypoglycemia.

Ethanol: Alcohol may prolong -- but not augment -- glipizide-induced reductions in blood glucose by delaying glipizide absorption and elimination. Chronic use of alcohol may decrease the half-life of tolbutamide. Alcohol ingestion by patients taking chlorpropamide may result in a disulfiram-like reaction. Pharmacists should counsel patients receiving sulfonylureas to avoid alcohol intake in excess of one drink. (Note: Metformin is not a sulfonylurea. However, alcohol is known to intensify the effect of metformin on lactate metabolism and should be avoided in patients taking metformin.) Gemfibrozil: Hypoglycemic effects of glyburide may be increased. In patients receiving glyburide, the pharmacist should consider monitoring blood glucose levels when gemfibrozil is added to or discontinued from treatment regimens. Glyburide doses should be adjusted accordingly.

Histamine H2 antagonists (cimetidine, ranitidine): Reduced clearance of sulfonylureas may result in hypoglycemia because these drugs inhibit sulfonylurea hepatic metabolism resulting in an accumulation of sulfonylurea. Physicians or pharmacists should monitor blood glucose closely and observe for signs of clinical hypoglycemia.

Salicylates: Hypoglycemic effects of sulfonylureas may be increased because salicylates reduce basal plasma glucose levels and enhance insulin secretion. If hypoglycemia develops while on a salicylate, pharmacists should consider asking the physician to decrease the sulfonylurea dose.