Amaryl Drug Interactions

If glimepiride is taken simultaneously with certain other medicinal products, both undesired increases and decreases in the hypoglycaemic action of glimepiride can occur. For this reason, other medicinal products should only be taken with the knowledge (or at the prescription) of the doctor.
Glimepiride is metabolised by cytochrome P4502C9 (CYP2C9). Its metabolism is known to be influenced by concomitant administration of CYP2C9 inducers (e.g., rifampicin) or inhibitors (e.g., fluconazole).
Results from an in vivo interaction study reported in literature show that glimepiride AUC is increased approximately 2-fold by fluconazole, one of the most potent CYP2C9 inhibitors. Based on experience with Amaryl and on what is known of other sulfonylureas, the following interactions must be considered.
Potentiation of the blood-glucose-lowering effect and, thus, in some instances hypoglycaemia may occur when one of the following medicines is taken, for example: phenylbutazone, azapropazone and oxyfenbutazone, insulin and oral antidiabetic products, such as metformin, salicylates and p-amino-salicylic acid, anabolic steroids and male sex hormones, chloramphenicol, certain long acting sulfonamides, tetracyclines, quinolone antibiotics and clarithromycin, coumarin anticoagulants, fenfluramine, disopyramide, fibrates, ACE inhibitors, fluoxetine, MAO-inhibitors, allopurinol, probenecid, sulfinpyrazone, sympatholytics, cyclophosphamide, trophosphamide and iphosphamides, miconazole, fluconazole, pentoxifylline (high dose parenteral), tritoqualine.
Weakening of the blood-glucose-lowering effect and, thus, raised blood sugar levels may occur when one of the following medicines is taken, for example: oestrogens and progestogens, saluretics, thiazide diuretics, thyroid stimulating agents, glucocorticoids, phenothiazine derivatives, chlorpromazine, adrenaline and sympathicomimetics, nicotinic acid (high doses) and nicotinic acid derivatives, laxatives (long term use), phenytoin, diazoxide, glucagon, barbiturates and rifampicin, acetazolamide.
H2 antagonists, beta-blockers, clonidine and reserpine may lead to either potentiation or weakening of the blood-glucose-lowering effect.
Under the influence of sympatholytic medicines such as beta-blockers, clonidine, guanethidine and reserpine, the signs of adrenergic counter-regulation to hypoglycaemia may be reduced or absent.
Alcohol intake may potentiate or weaken the hypoglycaemic action of glimepiride in an unpredictable fashion.
Glimepiride may either potentiate or weaken the effects of coumarin derivatives.
Colesevelam binds to glimepiride and reduces glimepiride absorption from the gastro-intestinal tract. No interaction was observed when glimepiride was taken at least for 4 hours before colesevelam. Therefore, glimepiride should be administered at least 4 hours prior to colesevelam.