Indications for JANUMET XR:
Adjunct to diet and exercise to improve glycemic control in patients with type 2 diabetes when treatment with both sitagliptin and metformin extended-release is appropriate. Limitations of use: not for treating type 1 diabetes or diabetic ketoacidosis. Not studied in patients with history of pancreatitis.
Adult:
Individualize. Swallow whole. Take once daily with a meal, preferably in the evening. Not currently treated with metformin: initially 100mg/1000mg daily. Previously on metformin alone: initially 100mg daily of sitagliptin plus metformin dose. Previously on metformin 850mg twice daily or 1000mg twice daily: start with two 50mg/1000mg tablets taken together once daily. Previously on Janumet: switch on a mg/mg basis. Max 100mg sitagliptin/2000mg metformin per day.
Children:
<18yrs: not established.
Pharmacological Class:
Dipeptidyl peptidase-4 inhibitor + biguanide.
Contraindications:
Renal impairment (Scr ≥1.5mg/dL [men], ≥1.4mg/dL [women], or abnormal CrCl). Metabolic acidosis, diabetic ketoacidosis.
Warnings/Precautions:
Confirm normal renal function before starting and monitor (esp. in elderly). Discontinue if lactic acidosis, renal impairment, shock, acute MI or CHF, sepsis, hypoxemia, pancreatitis, or hypersensitivity reactions occur. Avoid if clinical or lab evidence of hepatic disease. May need to suspend therapy during periods of stress or if dehydration occurs or before surgery. Monitor hematology (esp. serum Vit. B12 in susceptible patients). Elderly, debilitated, uncompensated strenuous exercise, malnourished or deficient caloric intake, adrenal or pituitary insufficiency, or alcohol intoxication: increased risk of hypoglycemia. History of angioedema to other DPP-4 inhibitors. Concomitant intravascular iodinated contrast agents (suspend during and for 48hrs after use). Pregnancy (Cat.B). Nursing mothers.
Interactions:
Caution with concomitant topiramate or other carbonic anhydrase inhibitors (eg, zonisamide, acetazolamide, dichlorphenamide); may induce metabolic acidosis. Cationic drugs eliminated by renal tubular secretion (eg, amiloride, digoxin, morphine, procainamide, quinine, quinidine, ranitidine, triamterene, trimethoprim, vancomycin); monitor. Avoid excessive alcohol intake (potentiates effects of metformin on lactate). Diuretics, steroids, estrogens, oral contraceptives, phenothiazines, phenytoin, thyroid products, nicotinic acid, sympathomimetics, calcium channel blockers, isoniazid, others may cause hyperglycemia. May need to lower dose of concomitant sulfonylurea or insulin to reduce risk of hypoglycemia. β-blockers may mask hypoglycemia.
Adverse Reactions:
Diarrhea, URTI, headache, nasopharyngitis, hypoglycemia, asthenia; lactic acidosis (rare, half of the cases are fatal).
Metabolism:
Sitagliptin: hepatic (CYP3A4, 2C8)
Elimination:
Renal (major), fecal.
How Supplied:
XR tabs 50mg/500mg, 50mg/1000mg—60, 180, 1000; 100mg/1000mg—30, 90, 1000
