Decitabine Mesylate – Uses, Dosage, Side Effects, Interaction

Mechanism of Action

Myelodysplastic syndromes (MDS) are a group of hematopoietic neoplasms that manifest in peripheral cytopenias and may eventually progress to secondary acute myeloid leukemia (sAML). Included in the over 45 genes commonly mutated in MDS patients are those involved in DNA methylation and histone modification, and it is well-established that alteration of the epigenetic landscape is a feature of myeloid leukemias. Decitabine is considered a prodrug, as it requires transport into cells and subsequent phosphorylation by distinct kinases to generate the active molecule 5-aza-2′-deoxycytidine-triphosphate, which is incorporated by DNA polymerase during DNA replication. Once incorporated into DNA, decitabine is recognized as a substrate by DNA methyltransferase enzymes (DNMTs), specifically DNMT1, but due to the presence of an N5 rather than C5 atom, traps the DNMT through the irreversible formation of a covalent bond. At low concentrations, this mode of action depletes DNMTs and results in global DNA hypomethylation while at high concentrations, it additionally results in double-strand breaks and cell death. The general hypothesis regarding decitabine’s therapeutic efficacy is that the global hypomethylation it induces results in the expression of previously silent tumour suppressor genes. However, there are other putative mechanisms also related to this change in DNA methylation, including indirect alteration of transcription through effects on transcription factors, indirectly altering histone modifications and chromatin structure, and activating pathways involved in DNA damage response. The overall effect of decitabine is a decrease in neoplastic cell proliferation and an increase in the expression of tumour suppressor genes.

Decitabine is a prodrug analogue of the natural nucleotide 2’-deoxycytidine, which, upon being phosphorylated intracellularly, is incorporated into DNA and exerts numerous effects on gene expression. The use of decitabine is associated with neutropenia and thrombocytopenia. In addition, decitabine can cause fetal harm in pregnant women; effective contraception and avoidance of pregnancy are recommended during treatment with decitabine.


  • Decitabine is indicated for the treatment of patients with myelodysplastic syndromes (MDS) including all French-American-British subtypes (refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, and chronic myelomonocytic leukemia), as well as for MDS scored as belonging to the intermediate-1, intermediate-2, or high-risk group in the International Prognostic Scoring System.
  • Treatment of adult patients with newly diagnosed de novo or secondary acute myeloid leukemia (AML), according to the World Health Organization (WHO) classification, who are not candidates for standard induction chemotherapy.
  • Decitabine is a cytosine analog and an intravenously administered antineoplastic agent used in the therapy of myelodysplastic syndromes.

Use In Cancer

Decitabine is approved to treat adults with:

Decitabine is also being studied in the treatment of other conditions and types of cancer. Decitabine is also available in tablet form.


  • decreased blood platelets
  • low levels of a type of white blood cell called neutrophils
  • pregnancy
  • a patient who is producing milk and breastfeeding


Strengths: 50 mg

Myelodysplastic Syndrome


  • 15 mg/m2 IV over 3 hours; repeat every 8 hours for 3 days; repeat this cycle every 6 weeks; patients may be premedicated with standard antiemetic therapy

If hematologic recovery (ANC 1,000/mcL or greater and platelets 50,000/mcL or greater) from a previous treatment cycle requires more than 6 weeks, then the next cycle should be delayed and dosing temporarily reduced by following this algorithm:

  • Recovery requiring more than 6, but less than 8 weeks: Delay dosing for up to 2 weeks and temporarily reduce the dose to 11 mg/m2 IV every 8 hours (33 mg/m2/day, 99 mg/m2/cycle) when restarting therapy
  • Recovery requiring more than 8, but less than 10 weeks: Assess patient for disease progression (by bone marrow aspirates); in the absence of progression, the dose should be delayed up to 2 more weeks and then reduced to 11 mg/m2 IV every 8 hours (33 mg/m2/day, 99 mg/m2/cycle) when restarting therapy, then maintained or increased in subsequent cycles as clinically indicated


  • 20 mg/m2 IV over 1 hour; repeat daily for 5 days; repeat this cycle every 4 weeks; patients may be premedicated with standard antiemetic therapy. If myelosuppression is present, subsequent treatment cycles should be delayed until there is hematologic recovery (ANC 1,000/mcL or greater and platelets 50,000/mcL or greater)
  • With either regimen, it is recommended that patients be treated for a minimum of 4 cycles; however, a complete or partial response may take longer than 4 cycles.
  • Perform complete blood and platelet counts prior to each cycle and as needed to monitor response and toxicity.
  • Perform liver chemistries and serum creatinine prior to initiation of therapy.

Dose Adjustments

  • If any of the following nonhematologic toxicities are present, decitabine treatment should not be restarted until the toxicity is resolved: 1) serum creatinine greater than or equal to 2 mg/dL; 2) SGPT, total bilirubin greater than or equal to 2 times ULN; and 3) active or uncontrolled infection.
  • Geriatric patients were generally dosed at the same level as younger adult patients. Dose adjustments for toxicity should be conducted as specified for the general population.

Administration advice:

  • Once prepared, the final product should be given as a continuous IV infusion over one hour; a central venous catheter is not required.
  • Premedication for the prevention of nausea and vomiting is not typically required but may be administered if necessary.

Side Effects

The Most Common

  • excessive tiredness
  • pale skin
  • headache
  • dizziness
  • confusion
  • fast heartbeat
  • difficulty falling asleep or staying asleep
  • weakness
  • shortness of breath
  • nausea
  • constipation
  • diarrhea
  • vomiting
  • stomach pain
  • heartburn or indigestion
  • painful sores in the mouth, or on the tongue or lips
  • red spots on the skin
  • rash
  • change in skin color
  • hair loss
  • joint or muscle pain
  • chest discomfort or chest wall pain
  • swelling of the hands, feet, ankles, lower legs, or stomach
  • pain, swelling, or redness at injection spot
  • unusual bleeding or bruising
  • hives
  • itching
  • difficulty breathing or swallowing
  • swelling of the face
  • sore throat, fever, chills, cough, or other signs of infection

More Common

  • Black, tarry stools
  • bladder pain
  • bleeding after defecation
  • bleeding gums
  • blood in the urine or stools
  • bloody or cloudy urine
  • blue lips and fingernails
  • blurred vision
  • body aches or pain
  • chest pain
  • chills
  • congestion
  • cough
  • coughing that sometimes produces a pink frothy sputum
  • decreased urination
  • difficult, burning, or painful urination
  • difficult, fast, or noisy breathing
  • dizziness, faintness, or lightheadedness when getting up from a lying or sitting position
  • drowsiness
  • dry mouth or throat
  • fainting
  • fast or irregular heartbeat
  • feeling unusually cold
  • fever
  • flushed, dry skin
  • frequent urge to urinate
  • fruit-like breath odor
  • headache
  • hives or welts, itching, skin rash
  • hoarseness
  • increased hunger
  • increased sweating
  • increased thirst
  • increased urination
  • lightheadedness
  • loss of appetite
  • loss of consciousness
  • lower back or side pain
  • mood or mental changes
  • muscle pain, cramps, spasms, or twitching
  • nausea
  • nervousness
  • numbness or tingling in the hands, feet, or lips
  • pain, redness, swelling, tenderness, or warmth on the skin
  • pale skin
  • pinpoint red spots on the skin
  • redness or pain at the catheter site
  • runny nose
  • seizures
  • shivering
  • small clicking, bubbling, or rattling sounds in the lung when listening with a stethoscope
  • small red or purple spots on the skin, lips or in the mouth
  • sneezing
  • sore mouth, tongue, or throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stomach pain and bloating
  • sunken eyes
  • swelling of the face, hands, ankles, feet, or lower legs
  • swollen, painful, or tender lymph glands in the neck, armpit, or groin
  • tightness in the chest
  • trembling
  • trouble in swallowing
  • troubled breathing with exertion
  • uncomfortable swelling around the anus
  • unexplained weight loss
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • voice changes
  • vomiting
  • weakness or heaviness of the legs
  • wrinkled skin
  • yellow eyes or skin


  • Collection of blood under the skin
  • deep, dark purple bruise
  • diarrhea
  • pain or tenderness around the eyes and cheekbones
  • pain, warmth, or burning in the fingers, toes, and legs
  • problems with vision or hearing
  • skin scrape or burn
  • stuffy nose
  • swelling at the injection site
  • muscle stiffness
  • pain in the arms or legs
  • pain in joints
  • stomach discomfort or upset
  • swelling or inflammation of the mouth
  • trouble sleeping
  • unusual drowsiness, dullness, or feeling of sluggishness
  • Difficulty in moving
  • general feeling of discomfort or illness
  • postnasal drip
  • pressure in the stomach
  • swollen joints

Drug Interaction

Pregnancy And Lactation

US FDA pregnancy category Not Assigned


If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus. Women of childbearing potential should be advised to use effective contraception and avoid becoming pregnant while being treated with this drug. The period following therapy when it is safe to become pregnant is unknown. Men should use effective contraception and be advised to not father a child while receiving this drug, and for 3 months following the last dose.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

How Should This Medicine Be Used?

Decitabine comes as a powder to be to be added to fluid and injected slowly over 3 hours intravenously (into a vein) by a doctor or nurse in a medical office or hospital outpatient clinic. It is usually injected every 8 hours for 3 days. This treatment period is called a cycle, and the cycle may be repeated every 6 weeks for as long as your doctor recommends. Decitabine should usually be given for at least four cycles but may be continued if your doctor decides that you will benefit from additional treatment.

Your doctor may also need to delay your treatment and reduce your dose if you experience certain side effects. Be sure to tell your doctor how you are feeling during your treatment with decitabine.

Your doctor will give you medication to prevent nausea and vomiting before you receive each dose of decitabine.

What Special Precautions Should I Follow?

Before receiving a dose of decitabine,

  • tell your doctor and pharmacist if you are allergic to decitabine or any other medications.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have kidney or liver disease.
  • tell your doctor if you are pregnant or plan to become pregnant, or if you plan to father a child. You or your partner should not become pregnant while you are using decitabine. You should use birth control to prevent pregnancy in yourself or your partner during your treatment with decitabine and for 2 months afterward. Talk to your doctor about birth control methods that will work for you. If you or your partner becomes pregnant while using decitabine, call your doctor. Decitabine may harm the fetus.
  • tell your doctor if you are breastfeeding.


  11. CAMEO Chemical Reactivity Classification
  12. ChemIDplus Chemical Information Classification
  13. CompTox Chemicals Dashboard Chemical Lists
  14. 4-amino-1-(2-deoxy-β-D-erythro-pentofuranosyl)-1,3,5-triazin-2(1H)-one
  15. NORMAN Suspect List Exchange Classification
  16. PubChem
  17. Antimetabolites, Antineoplastic
  18. Anatomical Therapeutic Chemical (ATC) classification
    Target-based classification of drugs
  19. NCBI