Leukemia--Acute Myeloid (Myelogenous)

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Treating Leukemia - Acute Myeloid (AML) TOPICS

Treatment of acute promyelocytic (M3) leukemia

Early diagnosis and treatment of acute promyelocytic leukemia (APL), the M3 subtype of acute myeloid leukemia (AML), is important because patients with APL may develop serious blood-clotting or bleeding problems. This used to be treated with blood-thinning medicines, but is less often a problem now that treatment includes drugs like all-trans-retinoic acid (ATRA). Other treatments might include transfusions of platelets or other blood products.


The treatment of most cases of APL differs from usual AML treatment. Initial treatment includes the non-chemotherapy drug, all-trans-retinoic acid (ATRA), which is a relative of vitamin A. ATRA is most often combined with an anthracycline chemotherapy (chemo) drug (daunorubicin or idarubicin), sometimes also with the chemo drug cytarabine (ara-c).

Another option is to give ATRA plus another drug called arsenic trioxide (Trisenox). This is often used in patients who can’t tolerate an anthracycline drug, but is an option for other patients as well.


As with other subtypes of AML, patients with APL then receive post-remission treatment. What drugs are used depends on what was given for induction. Some of the options include:

  • An anthracycline along with ATRA for a few cycles (sometimes different anthracyclines are used in different cycles)
  • An anthracycline plus cytarabine for at least 2 cycles
  • Arsenic trioxide for 2 cycles (over about 2½ months), then ATRA plus an anthracycline for 2 cycles
  • ATRA plus arsenic trioxide for several cycles


For some patients, consolidation may be followed by maintenance therapy with ATRA for at least a year. Sometimes low doses of the chemo drugs 6-mercaptopurine (6-MP) and methotrexate are given as well.

Side effects

The possible side effects from the chemotherapy part of this treatment are generally the same as those of standard AML induction chemotherapy. But both ATRA and arsenic can cause a problem called differentiation syndrome (it used to be called retinoic acid syndrome). Symptoms of this syndrome include:

  • Breathing problems due to fluid buildup in the lungs
  • Low blood pressure
  • Kidney damage
  • Severe fluid buildup elsewhere in the body

It can often be treated by stopping the drug for a while and giving a steroid such as dexamethasone.

Last Medical Review: 07/24/2013
Last Revised: 02/07/2014