Decitabine is a chemotherapy drug used to treat specific blood and bone marrow disorders. It belongs to a class of medications known as hypomethylating agents and is designed to interfere with the growth of cancerous cells. Decitabine is a synthetic version of cytidine, a natural molecule that is a component of DNA.
Medical Uses of Decitabine
Decitabine is primarily used to treat myelodysplastic syndromes (MDS). MDS are a group of disorders characterized by the bone marrow’s inability to produce a sufficient number of healthy, mature blood cells. This results in low counts of red blood cells, white blood cells, and platelets. The drug is indicated for various subtypes and risk levels of MDS.
The conditions decitabine treats can be newly diagnosed or previously treated. It is effective for both de novo MDS, which arises without a known cause, and secondary MDS, which may develop after radiation or chemotherapy for other cancers. Decitabine is also used to treat certain forms of acute myeloid leukemia (AML), particularly for older adults or those with health conditions who may not tolerate more intensive chemotherapy.
How Decitabine Works
The function of decitabine is rooted in a process called DNA methylation, a mechanism cells use to control gene activity. This process can be compared to a biological light switch, turning specific genes “on” or “off” without changing the DNA sequence itself. This is accomplished by adding a small molecule called a methyl group to the DNA, which is a normal part of cellular regulation.
In many cancers, the DNA methylation process becomes dysregulated. Genes that are supposed to suppress the formation of tumors can be turned “off” by an excessive amount of methylation, a state known as hypermethylation. When these tumor suppressor genes are silenced, cancer cells can grow and divide uncontrollably.
Decitabine works by reversing this process. As a cytidine analog, it is incorporated into the DNA of dividing cells during replication. Once embedded in the DNA, it traps enzymes called DNA methyltransferases, which are responsible for maintaining methylation patterns. This inhibition leads to reduced methylation, which turns the silenced tumor suppressor genes back “on” and restores their ability to control cell growth.
Treatment Administration and Monitoring
Decitabine is administered as an intravenous (IV) infusion in a hospital or specialized clinic. The medication is slowly dripped directly into a vein, ensuring it enters the bloodstream and circulates throughout the body. The specific dosage and infusion time vary based on the treatment plan developed by the medical team.
Treatment is delivered in cycles. A regimen involves receiving the infusion daily for a set number of consecutive days, often five. This treatment period is followed by a rest period of several weeks to allow the body, particularly the bone marrow, to recover. This cyclical approach is designed to maximize the drug’s effectiveness while managing its impact on healthy tissues.
Throughout the course of treatment, close monitoring is necessary. Patients undergo regular blood tests, such as a complete blood count (CBC), to track the levels of red blood cells, white blood cells, and platelets. This monitoring allows the healthcare team to assess the drug’s effect on the bone marrow and make necessary adjustments to the treatment plan.
Common Side Effects and Management
The side effects of decitabine are often related to its impact on the bone marrow. A reduction in white blood cells, a condition called neutropenia, is common and lowers the body’s ability to fight infections. To manage this risk, patients are advised to avoid large crowds, stay away from sick individuals, and practice good hand hygiene. Any sign of infection, especially a fever, should be reported to the medical team immediately.
Another frequent side effect is a drop in platelet count, known as thrombocytopenia. Because platelets are necessary for blood clotting, low levels increase the risk of bruising and bleeding. Patients should take steps to prevent injuries, such as using a soft-bristled toothbrush and an electric razor. Any unusual or prolonged bleeding should be brought to the attention of a healthcare provider without delay.
Anemia, a deficiency of red blood cells that causes fatigue and shortness of breath, can also occur. This side effect is monitored closely and may be managed with blood transfusions if red blood cell counts become too low.
Gastrointestinal issues are also commonly experienced by patients. Nausea and vomiting can occur, but these symptoms are often well-controlled with anti-sickness medications. Diarrhea and constipation may also be present, and a healthcare provider can recommend dietary changes or medications to manage them.
Other general side effects include fatigue, fever, and swelling, particularly in the limbs. A feeling of being generally unwell is not uncommon with this type of treatment. Patients are encouraged to rest when needed and maintain open communication with their medical team about any symptoms they experience.
Important Precautions During Treatment
It is important to provide the healthcare team with a complete list of all other medications being taken, including over-the-counter drugs, vitamins, and herbal supplements. Some substances can interact with decitabine, potentially affecting its efficacy or increasing the risk of side effects. The medical team can review this list to identify any potential interactions.
Decitabine can cause harm to a developing fetus, so patients must avoid becoming pregnant while receiving this treatment. Women of childbearing potential should use effective contraception during treatment and for a specified period after the final dose. Men receiving decitabine should also use effective contraception to prevent their partner from becoming pregnant.