Rosiglitazone/metformin Generic Name & Formulations
Rosiglitazone (as maleate), metformin HCl; 1mg/500mg, 2mg/500mg, 2mg/1000mg, 4mg/500mg, 4mg/1000mg; tabs.
Thiazolidinedione + biguanide.
Adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes. Limitations of use: not for treating type 1 diabetes or diabetic ketoacidosis. Not for use with insulin.
Rosiglitazone/metformin Dosage and Administration
Give in divided doses with meals. Drug-naive: initially 2mg/500mg once or twice daily; may increase by 2mg/500mg per day after 4 weeks; max 8mg/2000mg per day. If HbA1c >11% or fasting plasma glucose (FPG) >270mg/dL: consider starting at 2mg/500mg twice daily. Previously on metformin alone: add rosiglitazone 4mg/day to current metformin dose; may increase after 8–12 weeks. Previously on rosiglitazone alone: add metformin 1000mg/day to current rosiglitazone dose; may increase after 1–2 weeks. Previously on rosiglitazone + metformin: switch on a mg/mg basis; may increase by rosiglitazone 4mg and/or metformin 500mg per day; max 8mg/2000mg per day.
<18yrs: not established.
NYHA Class III or IV heart failure. Severe renal impairment (eGFR <30mL/min/1.73m2). Metabolic acidosis, diabetic ketoacidosis.
Rosiglitazone/metformin Boxed Warnings
Symptomatic HF or acute coronary syndromes: not recommended; discontinue if occurs. CHF: NYHA Class I or II: increased risk of cardiovascular events (monitor); discontinue or reduce dose if develops. Edema. Monitor for signs/symptoms of heart failure. Increased risk of metformin-associated lactic acidosis in renal or hepatic impairment, concomitant use of certain drugs (eg, cationic drugs), ≥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. Assess renal function prior to starting and periodically thereafter; more frequently in elderly or if eGFR <60mL/min/1.73m2. Hepatic impairment: not recommended. Do not initiate in active liver disease or if ALT >2.5xULN. Monitor LFTs at baseline, then periodically. Follow up and monitor closely if ALT is mildly elevated (≤2.5xULN); discontinue if ALT >3xULN or jaundice occurs. 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). Premenopausal women with anovulatory: ovulation may occur. Reevaluate if menstrual dysfunction occurs. Pregnancy (Cat.C), nursing mothers: not recommended; consider using insulin instead.
Concomitant insulin: not recommended. 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). Rosiglitazone may be potentiated by CYP2C8 inhibitors (eg, gemfibrozil) and antagonized by CYP2C8 inducers (eg, rifampin); may need to adjust dose. Diuretics, steroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, sympathomimetics, calcium channel blockers, isoniazid, nicotinic acid, others may cause hyperglycemia. May need lower dose of concomitant other hypoglycemic agents to reduce risk of hypoglycemia. β-blockers may mask hypoglycemia.
Rosiglitazone/metformin Adverse Reactions
Nausea, vomiting, diarrhea, headache, dyspepsia; hypoglycemia, edema, weight gain, anemia, macular edema, risk of fracture (esp. women); rare: lactic acidosis (may be fatal). See full labeling re: risk of myocardial ischemic events.
Rosiglitazone/metformin Clinical Trials
Formerly known under the brand name Avandamet.
Rosiglitazone/metformin Patient Counseling