RiteMED Glibenclamide Drug Interactions

The effect of sulfonylureas may be reduced by epinephrine, chlorpromazine, corticosteroids, oral contraceptives, thiazide diuretics and thyroid hormones.
Concomitant use with rifampicin reduces the hypoglycemic effect of glibenclamide.
In contrast, hypoglycemic effect may be heightened by ACE inhibitors, alcohol, allopurinol, selected analgesics such as phenylbutazone and salicylates, ketoconazole, fluconazole and miconazole, chloramphenicol, cimetidine, clofibrate, coumarins, fluoroquinolones, heparin, MAOIs, ranitidine, sulphonamides, tetracyclines and tricyclic antidepressants.
There were reports that beta-blockers may increase the hypoglycemic effect of glibenclamide and other sulfonylureas and may mask the typical sympathetic warning signs. However, a report that beta-blockers antagonize the hypoglycemic action of glibenclamide was also received. Beta-blockers are shown to have both hypoglycemic and intrinsic hyperglycemic activity of their own. Beta-blockers, when used in diabetic patients, might mask the early warning signs of hypoglycemia induced by the drug.
Reports on the effect of calcium channel blockers and sulfonylureas on glucose tolerance are contradictory. The effects, though, are clinically insignificant.