Drug Interaction Report

MONITOR: Because telbivudine is primarily eliminated by renal excretion, coadministration with drugs that affect renal function may alter the plasma concentrations of telbivudine and/or the coadministered drug.

MANAGEMENT: Caution is advised if telbivudine is prescribed in combination with potentially nephrotoxic drugs (e.g., aminoglycosides; polypeptide, glycopeptide, and polymyxin antibiotics; amphotericin B; adefovir; cidofovir; tenofovir; foscarnet; cisplatin; deferasirox; gallium nitrate; lithium; mesalamine; certain immunosuppressants; intravenous bisphosphonates; intravenous pentamidine; high intravenous dosages of methotrexate; high dosages and/or chronic use of nonsteroidal anti-inflammatory agents). Renal function should be evaluated prior to and during therapy with telbivudine. Adjustment of dosing interval is required in patients with renal insufficiency (creatinine clearance below 50 mL/min) at baseline or during treatment in accordance with the manufacturer's product labeling.

ADJUST DOSING INTERVAL: Consumption of food can decrease the rate and extent of gastrointestinal absorption of sirolimus. Also, the consumption of grapefruit juice may result in increased sirolimus trough concentrations.

MANAGEMENT: Experts recommend that this drug be taken either at least one hour prior to eating or consistently with or without food to avoid variations in sirolimus blood levels. The manufacturer recommends against using grapefruit juice for dilution of sirolimus doses. Patients should be monitored for clinical and laboratory evidence of altered immunosuppressant effects.