Indications for PRANDIMET:
Adjunct to diet and exercise in type 2 diabetes patients already treated with a glinide and metformin or who have inadequate glycemic control on a glinide alone or metformin alone. Limitations of use: not for treatment of type 1 diabetes or diabetic ketoacidosis.
Take within 30mins before food. Individualize. Give in 2–3 divided doses; titrate gradually. Previously on metformin alone: initially 1mg/500mg twice daily. Previously on glinide alone: initially add metformin component 500mg twice daily. Previously on both components: switch to similar doses of PrandiMet then titrate. Max 4mg/1000mg per meal, or 10mg/2500mg per day. Withhold drug if meal is skipped. Renal impairment: if eGFR between 30–45mL/min/1.73m2: do not initiate; if eGFR later falls <45mL/min/1.73m2: assess benefit/risk of continuing therapy; discontinue if eGFR later falls <30mL/min/1.73m2. Concomitant clopidogrel: avoid; if unavoidable, initiate repaglinide at 0.5mg before each meal (max repaglinide 4mg/day). Concomitant cyclosporine: max repaglinide 6mg/day.
Severe renal impairment (eGFR <30mL/min/1.73m2). Metabolic acidosis, diabetic ketoacidosis. Concomitant gemfibrozil.
Increased risk of metformin-associated lactic acidosis in renal or hepatic impairment, concomitant use of certain drugs (eg, carbonic anhydrase inhibitors), ≥65yrs of age, undergoing radiological contrast study, surgery and other procedures, hypoxic states, and excessive alcohol intake; discontinue if lactic acidosis occurs. Discontinue at time of, or prior to intravascular iodinated contrast imaging in patients with eGFR 30–60mL/min/1.73m2, history of hepatic impairment, alcoholism, heart failure, or will be given intra-arterial contrast; reevaluate eGFR 48hrs after procedure and restart therapy if renally stable. Suspend therapy if dehydration occurs or before surgery. Avoid if clinical or lab evidence of hepatic disease. Assess renal function prior to starting and periodically thereafter; more frequently in elderly or if eGFR <60mL/min/1.73m2. Elderly, debilitated, uncompensated strenuous exercise, malnourished or deficient caloric intake, adrenal or pituitary insufficiency, or alcohol intoxication: increased risk of hypoglycemia. Monitor hematology (esp. serum Vit. B12 in susceptible patients). Pregnancy (Cat.C). Nursing mothers: not recommended.
Glinide + biguanide.
See Contraindications. Not for use with NPH insulin. Increased risk of lactic acidosis with topiramate, other carbonic anhydrase inhibitors (eg, zonisamide, acetazolamide, dichlorphenamide); monitor. Concomitant cationic drugs that interfere with renal tubular transport systems (eg, ranolazine, vandetanib, dolutegravir, cimetidine) may increase metformin levels; monitor. Avoid excessive alcohol intake (potentiates effects of metformin on lactate). Potentiated by clopidogrel, cyclosporine, CYP3A4 inhibitors (eg, ketoconazole, itraconazole, erythromycin, clarithromycin), CYP2C8 inhibitors (eg, trimethoprim, montelukast, deferasirox); adjust dose and monitor (see Adult). Antagonized by CYP3A4 and/or CYP2C8 inducers (eg, carbamazepine, rifampin, barbiturates), atypical antipsychotics, CCBs, corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, protease inhibitors, somatropin, sympathomimetics, thyroid hormones; adjust dose and monitor. Antidiabetic agents, ACEIs, ARBs, disopyramide, fibrates, fluoxetine, MAOIs, NSAIDs, pentoxifylline, pramlintide, propoxyphene, salicylates, somatostatin analogs, sulfonamide antibiotics increase risk of hypoglycemia. β-blockers, clonidine, guanethidine, reserpine may mask hypoglycemia.
Hypoglycemia, headache, GI upset; rare: lactic acidosis (may be fatal).