Arsenic trioxide is used to treat acute promyelocytic leukemia in patients who have not responded to standard treatment.
Arsenic trioxide, like many other antineoplastic (antitumor) agents, acts by interfering with the growth of cells. Unfortunately, these drugs affect the growth of normal cells and tumor cells. In some patients the drug may have to be discontinued because normal cell growth is too severely affected. For example, a patient taking a large dose of arsenic trioxide might see tumor growth stop. However, the dosage might be high enough to also stop the body's normal growth of platelet cells. The loss of platelets might cause severe internal bleeding-a consequence more immediately toxic than the tumor.
Doses vary from individual to individual and depend on body weight as well as other medications the patient is taking. For acute promyelocytic leukemia dosages for adults and children five years of age and older are up to 60 injections of 0.15 mg/kg of body weight until bone marrow remission occurs.
Arsenic trioxide has been shown to cause fetal abnormalities and miscarriage in animals. Women who might become pregnant should take precautions to ensure they do not become pregnant while taking this drug. Women who are nursing their infants should discontinue nursing while this medication is in their system.
Patients with bone marrow problems, heart problems, kidney problems, or low levels of magnesium or potassium in the blood should notify their physician before taking any of this medicine. Patients should notify their physician of any illnesses they may have before taking arsenic trioxide.
Because persons taking arsenic trioxide may have decreased immunity, it is important for them to avoid infection. Caution should be taken to avoid unnecessary exposure to crowds and people with infections.
Patients may experience unusual or excessive bruising and/or bleeding and should avoid situations in which it is likely they could cut or bruise themselves. Patients should consult their physician immediately if they have any indication of excessive bleeding or bruising, including black and tarry stools, blood in the urine or stools, unusual bleeding or bruising, pinpoint red marks on their skin, vomit containing blood or what appears to be coffee grounds (dried blood). Severe symptoms may indicate a medical emergency.
Symptoms include unusual heartbeat (fast, slow, irregular, or pounding), chest pain, high blood pressure, trouble breathing, bluish lips, skin, palms, or skin underneath the fingernails, muscle cramps, numbness or tingling, headache, acting or feeling drunk, confusion, fainting, dizziness, eye pain, blurred vision, excessive weakness, excessive fatigue, or excessive drowsiness.
Patients should also contact their physician immediately if they experience a fruity odor in their mouth, a dry mouth, excessive sweating, flushing, urine retention, excessive urination, increased appetite or thirst, abdominal pain, loss of appetite, unexplained weight gain or loss, or severe nausea.
Patients may have vomiting, nausea, diarrhea, insomnia, sour stomach, heartburn, constipation, gas, neck pain, back pain, bone pain, bloating, swelling, pain or swelling at the injection site, joint, muscle, or limb pain, depression, or nosebleeds.
Patients should always notify their physician about any unusual symptoms they experience while on medication.
Patients should tell their doctors if they have a known allergic reaction to arsenic trioxide or any other medications or substances, such as foods and preservatives. Before taking any new medications, including non-prescription medications, vitamins, and herbal medications, the patients should notify their doctors.
Michael Zuck, Ph.D.
—A substance used to help prevent tumor growth.