imatinib (Gleevec)

Imatinib is an oral medication used for treating chronic myeloid leukemia and acute lymphoblastic leukemia. It is classified as a kinase inhibitor. Kinase inhibitors include dasatinib (Sprycel), erlotinib (Tarceva), gefitinib (Iressa), nilotinib (Tasigna), pazopanib (Votrient), sunitinib (Sutent), and vandetanib (Caprelsa). Kinase inhibitors prevent tumors from growing by reducing the action of proteins that control cell division, growth and survival. These proteins are usually present in larger quantities or are more active in cancer cells. By reducing the activity of these proteins, growth and survival of cancer cells are reduced. The FDA approved imatinib in April 2003.

What brand names are available for imatinib?

Gleevec

Is imatinib available as a generic drug?

No

Do I need a prescription for imatinib?

Yes

Common side effects include:

• fluid retention,
• headache,
• diarrhea,
• loss of appetite,
• weakness,
• nausea and vomiting,
• abdominal distention,
• swelling of arms and legs,
• rash,
• itching,
• fever,
• dizziness, and
• muscle pain.

Serious side effects include:

• fever associated with reduced white blood cells,
• reduced platelets
• reduced red blood cell counts,
• infection,
• stomach or intestinal bleeding,
• bleeding in the brain,
• heart failure,
• reduced liver function, and
• fluid in the lungs.

The recommended dose range is 300-800 mg orally daily depending on the condition being treated. All doses should be administered with a meal and a large glass of water. A dose of 800 mg should be administered as 400 mg twice daily. Doses less than 800 mg may be administered once daily. It can be dissolved in apple juice or water for those with difficulty swallowing.

The blood concentration of imatinib may be increased by several drugs that reduce its break down by the liver. Examples include ketoconazole, itraconazole (Sporanox), clarithromycin (Biaxin), atazanavir (Reyataz), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir), saquinavir (Invirase), telithromycin (Ketek), voriconazole (Vfend), and grapefruit juice. Increased blood concentrations of imatinib may increase the occurrence of adverse effects.

Certain drugs decrease the blood concentration of imatinib resulting in decreased blood levels and possibly reduced effect. Examples include carbamazepine, phenobarbital, rifampin, phenytoin, fosphenytoin, primidone, and St John's Wort.

Imatinib increases the blood concentration of simvastatin (Zocor) by reducing the activity of enzymes that break down simvastatin in the liver. This may increase the side effects of simvastatin. Imatinib may interact with other drugs that are broken down in a similar way as simvastatin.

Imatinib is harmful to the fetus and should not be used during pregnancy.

Imatinib is excreted in human milk; therefore, nursing mothers should either discontinue imatinib or stop breastfeeding.

What preparations of imatinib are available?

Tablets: 100, and 400 mg

How should I keep imatinib stored?

Imatinib should be stored at room temperature between 15 C - 30 C (59 F - 86 F).