Metformininteractions

The concomitant use of JANUMET XR with specific drugs may increase the risk of metformin-associated lactic acidosis: those that impair renal function, result in significant hemodynamic change, interfere with acid-base balance or increase metformin accumulation. Therefore, consider more frequent monitoring of patients.

7 DRUG INTERACTIONS Table 4 presents clinically significant drug interactions with JANUMET XR: Table 4: Clinically Significant Drug Interactions with JANUMET XR Carbonic Anhydrase Inhibitors Clinical Impact: Carbonic anhydrase inhibitors frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of these drugs with JANUMET XR may increase the risk for lactic acidosis.

Intervention: Consider more frequent monitoring of these patients.

Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide. Drugs that Reduce Metformin Clearance Clinical Impact: Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT 2 ] / multidrug and toxin extrusion [MATE] inhibitors) could increase systemic exposure to metformin and may increase the risk for lactic acidosis.

Intervention: Consider the benefits and risks of concomitant use with JANUMET XR.

Examples: Ranolazine, vandetanib, dolutegravir, and cimetidine.

Alcohol Clinical Impact: Alcohol is known to potentiate the effect of metformin on lactate metabolism.

Intervention: Warn patients against alcohol intake while receiving JANUMET XR. Insulin Secretagogues or Insulin Clinical Impact: Coadministration of JANUMET XR with an insulin secretagogue (e.g., sulfonylurea) or insulin may increase the risk of hypoglycemia.

Intervention: Patients receiving an insulin secretagogue or insulin may require lower doses of the insulin secretagogue or insulin. Drugs Affecting Glycemic Control Clinical Impact: Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control.

Intervention: When such drugs are administered to a patient receiving JANUMET XR, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving JANUMET XR, observe the patient closely for hypoglycemia.

Examples: Thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, and isoniazid. Carbonic anhydrase inhibitors may increase risk of lactic acidosis. Consider more frequent monitoring. Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin. Consider the benefits and risks of concomitant use. Alcohol can potentiate the effect of metformin on lactate metabolism. Warn patients against excessive alcohol intake.