Other drugs for acute myeloid leukemia

Acute promyelocytic leukemia (APL or AML M3) is different from other types of acute myeloid leukemia (AML) in some important ways. First, the leukemia cells (or blasts) contain proteins that when released into the bloodstream cause the blood to clot in an out-of-control way. This can lead to problems not only with blood clots, but also with severe bleeding. This was a big problem in the past, since treating APL with regular chemotherapy (chemo) drugs caused those cells to die and release these proteins into the bloodstream. Patients sometimes died from complications from the out-of-control clotting.

Then experts found that there were drugs that could fight the leukemia without leading to the clotting problems: all-trans-retinoic acid (ATRA, tretinoin, or Vesanoid^®) and arsenic trioxide ((ATO, Trisenox^®). These drugs are only used for this one type of AML known as APL -- they are not helpful for any other type. One or both of these drugs may be used as a part of the treatment of APL. Often, ATRA combined with chemo is the first treatment given.

Side effects

The most important side effect of either of these drugs is a syndrome known as retinoic acid syndrome or differentiation syndrome. It is most often only seen during the first cycle of treatment. Symptoms include breathing problems due to fluid buildup in the lungs and around the heart, low blood pressure, kidney damage, and severe fluid buildup elsewhere in the body. It can often be treated by stopping the drugs for a while and giving a steroid.

ATRA can also have side effects like those seen if you take too much vitamin A. Symptoms include headache, fever, dry skin and mouth, skin rash, swollen feet, sores in the mouth or throat, itching and irritated eyes. It can also cause blood lipid levels (like those of cholesterol and triglycerides) to go up. These side effects often go away when the drug is stopped.

Most side effects of arsenic trioxide are mild and can include tiredness, nausea and vomiting, diarrhea, stomach pain, and nerve damage leading to numbness and tingling in the hands and feet. It can also cause problems with heart rhythm, which can be serious. This is why your doctor may check your EKG often (even daily) while you are getting this drug.