Imatinib

1 medicine

Imatinib is a targeted cancer drug used mainly for chronic myeloid leukemia and gastrointestinal stromal tumors; it blocks a specific abnormal growth signal and requires regular blood counts and liver checks throughout treatment.

Gleevec

Imatinib

100/400mg

Gleevec is a oncology medication containing Imatinib, available as 100/400mg tablets.

from $3.89 / tablet View

Key facts

  • Imatinib (sold as Glivec or Gleevec) is a tyrosine-kinase inhibitor: it blocks an abnormal growth signal found in specific cancer cells, rather than attacking all dividing cells.
  • It's taken as a tablet once or twice daily, with food and a full glass of water, often for years or indefinitely depending on your response.
  • Regular blood counts and liver function tests are required throughout treatment to catch low blood cell counts or liver injury early.
  • Seek urgent care for sudden weight gain, severe swelling, shortness of breath, or signs of bleeding.

What imatinib treats

Imatinib treats chronic myeloid leukemia (CML), a blood cancer driven by an abnormal gene fusion (the Philadelphia chromosome) that causes the bone marrow to make too many abnormal white blood cells. It also treats gastrointestinal stromal tumors (GIST), tumors that arise in the wall of the stomach or intestine, and Philadelphia-chromosome-positive acute lymphoblastic leukemia. These are its established, licensed uses.

How imatinib works

The cancers imatinib treats are driven by an abnormal protein, a tyrosine kinase, that stays permanently switched on, sending a continuous signal for the cell to grow and divide. Imatinib fits into that protein and blocks the signal, which slows or stops the growth of cells carrying the abnormal gene while largely sparing normal cells that don't depend on it.

Before you take it

  • Tell your doctor about liver or kidney disease, heart failure, or a history of low blood counts before starting.
  • Imatinib can cause fluid retention; report sudden swelling, rapid weight gain, or shortness of breath.
  • Many common medicines change imatinib levels, including some antifungals, anticonvulsants, and St John's wort; tell every prescriber you take it.
  • Avoid grapefruit juice, which can raise imatinib levels.
  • Reliable contraception is needed during treatment, since imatinib can harm a developing fetus.

Side effects

Common effects include nausea, diarrhea, muscle cramps, fluid retention around the eyes or ankles, and skin rash.

Stop and seek urgent medical care for any of these:

  • Sudden weight gain, severe swelling, or shortness of breath (possible fluid retention affecting the heart or lungs).
  • Unusual bruising or bleeding, or signs of infection such as fever.
  • Yellowing of the skin or eyes, or severe abdominal pain (possible liver injury).
  • Severe skin rash or blistering.

Safety essentials

  • Regular blood counts and liver function tests are required throughout treatment, since imatinib can suppress bone marrow and affect the liver, sometimes without early symptoms.
  • Fluid retention is common and can become serious; report swelling or breathlessness rather than waiting for it to pass.
  • Do not stop or change your dose without talking to your specialist: CML and GIST need consistent, monitored treatment to keep the abnormal growth signal blocked.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.