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