Risk factors for toxicity
Sulfonylurea drugs are substrates for the cytochrome P450 drug metabolising system enzyme, CYP2C9. People taking drugs that inhibit CYP2C9, are more susceptible to the toxic effects of sulfonylurea drugs (ie hypoglycaemia) because enzyme inhibition can raise serum sulfonylurea concentrations and prolong half-life1. However, this effect is more relevant in the context of therapeutic interactions than in poisoning.