Eltrombopaginteractions

7.1 Polyvalent

Cations (Chelation) Eltrombopag chelates polyvalent cations (such as iron, calcium, aluminum, magnesium, selenium, and zinc) in foods, mineral supplements, and antacids. Take eltrombopag tablets at least 2 hours before or 4 hours after any medications or products containing polyvalent cations, such as antacids, dairy products, and mineral supplements to avoid significant reduction in absorption of eltrombopag due to chelation.

7.2 Transporters

Use caution when concomitantly administering eltrombopag and drugs that are substrates of OATP1B1 (e.g., atorvastatin, bosentan, ezetimibe, fluvastatin, glyburide, olmesartan, pitavastatin, pravastatin, rosuvastatin, repaglinide, rifampin, simvastatin acid, SN-38 [active metabolite of irinotecan], valsartan) or breast cancer resistance protein (BCRP) (e.g., imatinib, irinotecan, lapatinib, methotrexate, mitoxantrone, rosuvastatin, sulfasalazine, topotecan). Monitor patients closely for signs and symptoms of excessive exposure to the drugs that are substrates of OATP1B1 or BCRP and consider reduction of the dose of these drugs, if appropriate. In clinical trials with eltrombopag, a dose reduction of rosuvastatin by 50% was recommended.

7.3 Protease

Inhibitors HIV Protease Inhibitors: No dose adjustment is recommended when eltrombopag is co-administered with lopinavir/ritonavir (LPV/RTV). Drug interactions with other HIV protease inhibitors have not been evaluated. Hepatitis C Virus Protease Inhibitors: No dose adjustments are recommended when eltrombopag is co-administered with boceprevir or telaprevir. Drug interactions with other hepatitis C virus (HCV) protease inhibitors have not been evaluated.

7.4 Peginterferon

Alfa-2a/b Therapy No dose adjustments are recommended when eltrombopag is co-administered with peginterferon alfa-2a (PEGASYS ® ) or -2b (PEGINTRON ® ).

7.5 Interference with

Clinical Laboratory Tests Eltrombopag is highly colored and can cause patient sample discoloration, which is reported to interfere with some clinical laboratory tests, including, but not limited to bilirubin and creatinine.

Bilirubin Testing: Eltrombopag can cause both positive and negative interference with bilirubin assays. If the laboratory results for bilirubin are inconsistent with clinical observations, further evaluation of liver function should be performed to clarify the clinical status of the patient. Evaluating contemporaneous aminotransferase values (AST, ALT) may help determine the validity of normal total bilirubin levels in the presence of clinical jaundice.

Creatinine Testing: Eltrombopag can cause positive interference with creatinine measurements, leading to falsely elevated creatinine levels. In the event of an unexpected serum creatinine test result, further evaluation of renal function should be performed. Blood urea should be evaluated if serum creatinine is unexpectedly high. Communicate to the lab conducting testing if the patient is taking eltrombopag. Re-testing using other methods may also help in determining the validity of the test results.