ORAL ANTIDIABETIC AGENTS
Seven categories of oral antidiabetic agents are now available in the USA for the treatment of persons with type 2 diabetes: insu-lin secretagogues (sulfonylureas, meglitinides, D-phenylalanine derivatives), biguanides, thiazolidinediones, α-glucosidase inhib-itors, incretin-based therapies, an amylin analog, and a bile acid-binding sequestrant. The sulfonylureas and biguanides have been available the longest and are the traditional treatment choice for type 2 diabetes. Novel classes of rapid-acting insulin secretagogues, the meglitinides and D-phenylalanine derivatives, are alternatives to the short-acting sulfonylureas. Insulin secret-agogues increase insulin secretion from beta cells. Biguanides decrease hepatic glucose production. The thiazolidinediones reduce insulin resistance. The incretin-based therapies control post-meal glucose excursions by increasing insulin release and decreasing glucagon secretion. The amylin analog also decreases post-meal glucose levels and reduces appetite. Alpha-glucosidase inhibitors slow the digestion and absorption of starch and disac-charides. Although still speculative, the mechanism of bile acid sequestrant’s glucose-lowering effect is presumed to be related to a decrease in hepatic glucose output.