OBJECT DRUGS

• Methotrexate
• Pralatrexate (Folotyn)

PRECIPITANT DRUGS

Proton Pump Inhibitors:

• Dexlansoprazole (Kapidex)
• Esomeprazole (Nexium, etc.)
• Lansoprazole (Prevacid, etc.)
• Omeprazole (Prilosec, etc.)
• Pantoprazole (Protonix, etc.)
• Rabeprazole (Aciphex)

Comment:

In patients receiving antineoplastic doses of methotrexate, several proton pump inhibitors (PPIs) have been associated with methotrexate toxicity such as bone marrow suppression and GI toxicity. The risk with low-dose methotrexate (e.g., for arthritis) is probably much lower, but one should still be alert for evidence of methotrexate toxicity. Although there is much less information on potential interactions of pralatrexate with PPIs, pralatrexate is similar to methotrexate, and one should assume that it may interact as well until clinical evidence is available.

Class 2: Use Only if Benefit Felt to Outweigh Risk

• Use Alternative: H₂-receptor antagonists are not known to interact with methotrexate, and may be safer alternatives to PPIs. Nonetheless, one should still monitor for altered methotrexate or pralatrexate effect if H₂-receptor antagonists are used.
• Monitor: Monitor for altered methotrexate or pralatrexate effect if a renal tubular secretion inhibitor is initiated, discontinued, or changed in dose.