OBJECT DRUGS

Antidiabetic Agents:

(CYP2C9 Substrates):

• Chlorpropamide (Diabinese)
• Glimepiride (Amaryl)
• Glipizide (Glucotrol, etc.)
• Glyburide (DiaBeta, Glucovance, etc.)
• Nateglinide (Starlix)
• Rosiglitazone (Avandia)
• Tolbutamide (Orinase)

PRECIPITANT DRUGS

Enzyme Inducers:

• Barbiturates
• Bosentan (Tracleer)
• Carbamazepine (Tegretol, etc.)
• Dabrafenib (Tafinlar)
• Enzalutamide (Xtandi)
• Fosphenytoin (Carebyx)
• Phenytoin (Dilantin, etc.)
• Primidone (Mysoline)
• Rifabutin (Mycobutin)
• Rifampin (Rifadin, etc.)
• Rifapentine (Priftin)
• St. John's wort

Comment:

Most enzyme inducers increase the activity of CYP2C9 and mauy increase the metabolism of antidiabetics metabolized by CYP2C9. For example, glyburide plasma concentrations are substantially reduced in the presence of bosentan. Also, the bosentan label states that concomitant use of glyburide and bosentan is contraindicated due to liver enzyme elevations observed during concomitant use.

Class 2: Use Only if Benefit Felt to Outweigh Risk

• Use Alternative: If possible use an alternative to either the antidiabetic agent or the enzyme inducer.
• Monitor: If the combination is used, monitor for reduced antidiabetic effect, and if the combination is glyburide and bosentan, monitor liver enzymes for evidence of hepatotoxicity