Generic diabetes drugs
Some of the drugs prescribed to treat diabetes are available as generics, including the following:
- Acetohexamide, a little-used first-generation sulfonylurea, is available in generic form only. (First-generation sulfonylureas have a greater risk of drug interactions.)
- Tolazamide (Tolinase), also a first-generation sulfonylurea, is available in generic form.
- Glipizide, which is sold under the brand names Glucotrol and Glucotrol XL, is also available in generic form.
- Glyburide, sold as DiaBeta, Micronase, and Glynase, is also available as a generic.
- Glimepiride (Amaryl) is available in generic form.
- Several generic versions of the drug metformin (previously sold only as Glucophage or Glucophage XR) are now available. The combinations of metformin and glyburide (Glucovance) and metformin and glipizide (Metaglip) are available as generic drugs. The combinations of metformin and rosiglitazone (Avandamet), metformin and pioglitazone (Actoplus Met), metformin and sitagliptin (Janumet), and metformin and repaglinide (PrandiMet), however, are still sold only as brand-name products.
The diabetes drugs not yet available as generics include the following:
- Neither of the alpha-glucosidase inhibitors (drugs that slow the breakdown of carbohydrate in the small intestine), acarbose (Precose) and miglitol (Glyset), is available in generic form. The patent on Precose runs out in 2007, and the patent on Glyset expires in 2009.
- Neither of the currently available thiazolidinediones (drugs that increase insulin sensitivity), rosiglitazone (Avandia) and pioglitazone (Actos), is available as a generic. The various patents on Avandia run out in 2008, 2015, and 2017, and the patents on Actos expire in 2011 and 2016.
- Neither repaglinide (Prandin) nor nateglinide (Starlix) (both of which spur the pancreas to release more insulin quickly after meals) has a generic form. Prandin’s patents expire in 2006 and 2009, and the various patents on Starlix expire in 2006, 2012, 2013, and 2019.
- Neither pramlintide (Symlin) nor exenatide (Byetta), two injectable drugs that were approved by the FDA in 2005 and act like hormones in the body, has a generic form. Patents on Symlin expire between 2009 and 2018, and patents on Byetta expire between 2013 and 2020.
- The new diabetes drug sitagliptin (Januvia), first in a class of drugs called DPP-4 inhibitors (which promote insulin secretion and prevent the release of glucose when blood glucose levels are elevated), is not available as a generic. Various patents on Januvia expire in 2017, 2019, and 2022.
- Insulin is not available in generic form. Click here to read why.
Patent dates hint at when brand-name drugs may become available as generics, but they really represent only ballpark estimates, because patent extensions and patent infringement lawsuits could delay FDA approval of generics by 30 months or more.
The right prescription
If you take a brand-name medicine for which there is an equivalent generic and you are interested in saving some money on drugs, talk with your doctor and pharmacist about the possibility of switching to a generic. They may think it’s a great idea, or they may have some convincing arguments against switching. Conversely, if you have tried both brand-name and generic versions of a drug and the brand-name version seems to work better for you, discuss this with your doctor. He may be willing to write “Do not substitute” on the prescription. (Depending on the laws of your state, your pharmacist may be empowered to offer you the generic equivalent of a brand-name drug. To prevent such a substitution, your physician may need to write “Do not substitute” or something similar on your prescription.)