Is Glyburide Obsolete?
Since the 1980’s glyburide has been a mainstay in the treatment of type 2 diabetes, and largely because of the increasing awareness of the risks of hypoglycemia and the availability of newer medications, both oral and injectable for the treatment of type 2 diabetes the use of glyburide and other sulfonylurea medications like glimepiride and glipizide has fallen from favor by many experts treating type 2 diabetes.
In fact the latest American Diabetes Association guidelines for the treatment of type 2 diabetes recommends metformin as the initial drug of choice for patients with type 2 diabetes for whom non-insulin therapy is appropriate. If adequate glycemic control is not achieved with metformin a second medication is recommended, and although the sylfonylureas are listed in the options in these recommendations many experts are leaning towards use of alternative drugs because of the side effects and lack of long term efficacy of glyburide and the other sylfonylureas.
The list of options, excluding insulin which is sometimes the option of choice, for add-on therapy to metformin or for use when metformin is contraindicated or poorly tolerated is extensive. The GLP-1 agonists (incretin mimetics) include Exenatide and Liraglutide (Byetta and Victoza) trade names respectively) have the advantages of possible weight loss and the potential for improved beta cell function, but the disadvantages of high cost, need for injection, possible side effects of pancreatitis, and lack of long-term safety information. (note C-cell hyperplasia and medullary thyroid tumors have been noted in lab animals). DPP-4 inhibitors (incretin enhancers) include several oral options like Januvia and Onglyza, and have the advantages of not requiring injections, being weight neutral, and not causing hypoglycemia, although their long-term safety also is unknown, and they are also quite expensive. An older option that has been less utilized since the advent of the above incretin system functioning drugs include the thiazolidinedione Actos (note Avandia has been removed from the market due to cardiovascular risks) which has recently been approved as a generic drug. Actos has the drawbacks of weight gain, edema, heart failure and the possibility of increased cardiovascular events as potential side effects. It has the advantage of not causing hypoglycemia, being well tolerated in patients at low risk of cardiovascular disease and congestive heart failure, and that now as a generic drug its cost is likely to be lower than the newer branded choices. Other options include the alpha-glucosidase inhibitors acarbose and miglitol, the meglitinides repaglinide and nateglinide, the bile acid sequestrant colesevelam (Cholestipol) and various combinations of these.
Use of glypizide is often recommended as for use only as a third or fourth medication when something more is required in order to try to avoid the use of insulin. Some experts feel that the addition of insulin is more effective and safer than the use of glyburide, but many still consider use of glyburide an option especially in low dosage when multiple oral medications are required for glycemic control of type 2 diabetics.
Some experts feel that glyburide is more effective in overweight patients with type 2 diabetes than in diabetics near their ideal body weight, although the documentation of this phenomenon is suboptimal. In summary the use of glyburide is currently not felt to be obsolete, although the use of glyburide as an oral agent in the treatment of type 2 diabetes has certainly become less in favor among diabetes experts, and alternatives are more and more becoming the norm.