Potentiation of the hypoglycemic action of the drug may occur with the concomitant administration of sulfonamides, salicylates, phenylbutazone, beta-adrenoreceptor-blocking agents, MAOIs, ketoconazole and miconazole. Diminution of hypoglycemic action of the drug may occur with the concomitant administration of thiazide diuretics, corticosteroids and estrogens. Adjustment of dosage of hypoglycemic agents may be required in patients suffering from intercurrent infections, traumas, shock of after anesthesia. When major surgery is to be performed, insulin therapy should be substituted for oral hypoglycemics.