OBJECT DRUGS

• Ranolazine (Ranexa)

PRECIPITANT DRUGS

Enzyme Inducers:

• Barbiturates
• Bosentan (Tracleer)
• Carbamazepine (Tegretol, etc.)
• Dabrafenib (Tafinlar)
• Dexamethasone (Decadron, etc.)
• Efavirenz (Sustiva)
• Lumacaftor (Orkambi)
• Oxcarbazepine (Trileptal, etc.)
• Phenytoin (Dilantin, etc.)
• Primidone (Mysoline)
• Rifabutin (Mycobutin)
• Rifampin (Rifadin, etc.)
• Rifapentine (Priftin)
• St. John's wort

Comment:

Ranolazine is metabolized by CYP3A4 and concurrent administration with CYP3A4 inducers has been shown to markedly reduce ranolazine plasma concentrations. Rifampin, for example, reduced ranolazine plasma concentrations by about 95%. Reduced ranolazine efficacy is likely to occur during coadministered with CYP3A4 inducers. The ranolazine label states that enzyme inducers are contraindicated with ranolazine.

Class 2: Use Only If Benefit Felt to Outweigh Risk

• Use Alternative: Avoid using CYP3A4 inducers in patients receiving ranolazine, since ranolazine plasma concentrations are likely to be subtherapeutic. The product information states that ranolazine should not be used with CYP3A4 inducers.
• Monitor: If concurrent use of ranolazine and CYP3A4 inducers is deemed to be necessary, monitor for altered ranolazine response when the CYP3A4 inducer is initiated, discontinued, or changed in dosage. Much larger than normal ranolazine dosage is likely to be required to achieve therapeutic ivabradine plasma concentrations.