[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Antimetabolites](https://durgical.com/en/pharmacology/classes/antimetabolites/) › Decitabine # Decitabine ## Antimetabolites? Antimetabolites ## High alert? An error with this medicine can cause serious harm: double checks and protocols are used. Cytidine analogue that blocks DNA methylation and lets silenced genes work again. Used for myelodysplastic syndromes; its main toxicity is low blood counts. Updated Nov 1, 2026 Also called: 5-aza-2′-deoxycytidine ## Quick facts **Group** [Antimetabolites](https://durgical.com/en/pharmacology/classes/antimetabolites/) **Target** DNA methyltransferase 1 (DNMT1), trapped on DNA after the drug is built into it **Used for** Myelodysplastic syndromes · The oral combination **Key effects** Neutropenia · Fever · Nausea **Monitor** Complete blood count · Signs of infection and bleeding **ATC** L01BC08 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Clinical What the labels mean - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action Decitabine enters the cell, is phosphorylated and is built into new DNA in place of deoxycytidine. When DNA methyltransferase tries to methylate the altered base, the enzyme stays covalently bound and is used up. Each round of replication then leaves the DNA less methylated, so tumour-suppressor and differentiation genes that were silenced can be expressed again; the cells mature or die by apoptosis. The DNA-protein adducts can also cause double-strand breaks. - Decitabine is phosphorylated and built into new DNA - DNA methyltransferase is trapped on it and depleted - DNA loses methylation; silenced genes switch back on - Abnormal marrow cells mature or die ## Indications - Myelodysplastic syndromes, new or previously treated, de novo or secondary. [Myelodysplastic syndromes →](https://durgical.com/en/conditions/myelodysplastic-syndromes/) - The oral combination with cedazuridine is also used in chronic myelomonocytic leukaemia and acute myeloid leukaemia. [Acute leukaemia (AML and ALL) →](https://durgical.com/en/conditions/acute-leukaemia/) ## Adverse effects ### Common - Neutropenia, thrombocytopenia and anaemia (the most common effects) - Fever, tiredness - Nausea, constipation, diarrhoea - Cough, petechiae - High blood glucose ### Serious (rare, important) - Severe, sometimes fatal myelosuppression with febrile neutropenia and infections such as pneumonia - Bleeding from low platelets, including intracranial haemorrhage - Differentiation syndrome, interstitial lung disease and Sweet syndrome (reported after marketing) ## Contraindications - The label lists none; pregnancy is avoided because it can harm the fetus ## Key interactions **CYP substrates, inhibitors and inducers** No CYP interactions are expected: decitabine is not a CYP substrate and does not inhibit or induce these enzymes in laboratory studies. **Other myelosuppressive treatments** Add to the fall in blood counts, the drug's main toxicity. ## What is monitored - Complete blood count with platelets before each cycle and as needed - Liver panel and serum creatinine at baseline - Signs of infection and bleeding ## Administration and safety - Intravenous infusion only, given in a clinic or hospital. - If it will not be given soon after mixing, it is diluted with cold infusion fluid and kept refrigerated for a limited time. - Hazardous drug: prepared and disposed of under cytotoxic-drug procedures. - Premedication against nausea is given before each dose. ## Pregnancy and breastfeeding Can cause fetal harm; pregnancy is avoided during treatment and for a period afterwards, and breastfeeding is not advised. ## Nursing care - Check the blood count before each cycle; cycles are often delayed for low counts. - Teach the patient to report fever, chills, cough, bruising or bleeding at once. - Watch blood glucose and ask about thirst and frequent urination. - Effective contraception for women and for men with female partners, during and after treatment. ## Pharmacokinetics **Absorption** Given intravenously. An oral form combines it with cedazuridine, a cytidine deaminase inhibitor that protects it from breakdown in the gut and liver. **Metabolism** Deaminated by cytidine deaminase, mainly in the liver but also in granulocytes, gut lining and blood; it is not a CYP substrate. **Half-life** Short in plasma, about half an hour, but its effect on DNA lasts much longer. ## Memory aid DE-CITabine DE-methylates: it traps the methylase on the DNA, the genes wake up and the marrow matures. Same toxicity as the rest of the family: the counts fall. ## Test yourself Think of the answer, then tap the question to see it. ## How does decitabine lower DNA methylation? It is built into DNA, where DNA methyltransferase binds it covalently and is used up; new DNA strands are then left unmethylated. ## For which group of diseases is intravenous decitabine approved? Myelodysplastic syndromes. ## Why does the oral form of decitabine include cedazuridine? Cedazuridine inhibits cytidine deaminase, the enzyme that would otherwise break decitabine down before it reaches the blood. ## What is the most frequent reason to delay or reduce decitabine? Myelosuppression: neutropenia, thrombocytopenia and anaemia. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/decitabine/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## What the labels mean **High alert** An error with this medicine can cause serious harm: double checks and protocols are used. ## Connections ## Related drugs 2 - [Azacitidine](https://durgical.com/en/pharmacology/azacitidine/) - [Cytarabine](https://durgical.com/en/pharmacology/cytarabine/) ## Related conditions 2 - [Myelodysplastic syndromes](https://durgical.com/en/conditions/myelodysplastic-syndromes/) - [Acute leukaemia (AML and ALL)](https://durgical.com/en/conditions/acute-leukaemia/) [← Back to the class: Antimetabolites](https://durgical.com/en/pharmacology/classes/antimetabolites/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - DECITABINE injection, powder, lyophilized, for solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=749f8d8c-e378-42a1-b94a-136b606dadb4) (DailyMed (U.S. National Library of Medicine), 2026); [Decitabine and Cedazuridine: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a620050.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L01BC08) (WHO Collaborating Centre for Drug Statistics Methodology, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/decitabine/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/decitabine/