drug interactions

Last reviewed 01/2018

Sulphonylureas are subject to a number of interactions although these are rarely important clinically. There hypoglycaemic effects can be altered by:

  • pharmacodynamic interactions with:
    • glucocorticoids
    • beta-blockers

  • pharmacokinetic interactions by 3 mechanisms:
    • reduction in renal elimination for example by allopurinol
    • reduction or acceleration of hepatic metabolism by cimetidine, or carbamazepine and phenytoin, respectively
    • displacement from protein binding sites - sulphonylureas are up to 99% protein bound - for example by salicylates