Sulfonylurea drugs (eg Glimepiride and Glipizide) are used to treat type 2 diabetes. Sulfonylureas lower blood sugar by causing the pancreas to produce insulin. This class of drugs have been a cornerstone of Type 2 diabetes pharmacotherapy for over 50 years. Sulfonylureas are broken down in the body by an enzyme called cytochrome P450 (CYP) which is encoded by the CYP2C9 gene. Mutations in this gene can lead to reduced ability to clear sulfonylurea drugs from the body.
One study1 assessed the impact of the combined CYP2C9*2 and CYP2C9*3 genotypes on sulfonylurea response. They found that patients with two copies of a loss-of-function allele were 3.4 times more likely to achieve a treatment hemoglobin A1c level than patients with two wild-type CYP2C9 alleles. In other words, type 2 diabetes patients with variant genotypes of CYP2C9 were found to respond better to treatment with Sulfonylureas drugs than those with the normal genotype.
The presence of this genotype could also predisose these individuals to a greater likelyhood for adverse reactions from Sulfonylurea drugs. Another study 6 suggested that individuals with genotypes predicting low CYP2C9 activity may be at a higher risk of severe drug-associated hypoglycaemia (low blood sugar).
Glibenclamide, Glimepiride, Glipizide, Tolbutamide, Chlorpropamide, Tolazamide, Glipizide/Metformin, Glyburide/Metformin, Pioglitazone/Glimepiride, Rosiglitazone/Glimepiride