Azacitidine

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Azacitidine

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Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Azacitidine

Property Description
Active ingredient Azacitidine (5-azacytidine)
Form Lyophilized powder for injection
Pharmacological class Hypomethylating Agent, Antimetabolite
Common use Systemic treatment for specific blood disorders
Origin Synthetic nucleoside analog

Azacitidine is a prescription-only medicine that functions as a potent antineoplastic agent in hematology. It is classified as a synthetic nucleoside analog, specifically a pyrimidine analog, meaning it is a man-made molecule structurally similar to the natural building blocks of DNA and RNA. This structural similarity allows the drug to exert a targeted, systemic effect on rapidly dividing, abnormal cells, thereby establishing its role as a chemotherapeutic agent.


What Type of Medicine is Azacitidine? (Identity and Classification)

Azacitidine is classified as a hypomethylating agent and an antimetabolite. Its primary mechanism involves acting as a DNA methyltransferase inhibitor, a high-level physiological action that alters the "epigenetic" control system of the cell by reversing the process of DNA methylation. This mechanism is clinically recognized for its ability to modify gene expression in certain types of cancer cells. The systemic treatment is intended to encourage proper cell differentiation induction and eliminate over-proliferating or dysfunctional cells, establishing its high-level general purpose for managing certain hematologic conditions in adults.


Composition and Physical Form (Preparation and Delivery)

The active ingredient, Azacitidine (5-azacytidine), is supplied as a sterile lyophilized powder for injection. This formulation is a single active ingredient product, ensuring that its systemic delivery is precise and controlled. Its identity is intrinsically linked to its required delivery: it is administered exclusively through parenteral administration, via either a subcutaneous injection or an intravenous infusion. This specific preparation and route ensure that the therapeutic concentration of the cytostatic compound is reliably achieved at the systemic sites of action within the body.

Regulatory References

  1. National Cancer Institute Drug Dictionary: Azacitidine
  2. EMA Public Summary for Vidaza (Azacitidine)

What side effects are possible with Azacitidine?

Possible Side Effects and Safety Information

The safety profile of Azacitidine is formally defined by regulatory documents, reflecting its action as a systemic antineoplastic agent. Adverse reactions are classified by frequency and by the physiological system they affect, guiding the understanding of expected risks during treatment.

Frequency and Systemic Effects

Adverse reactions are primarily clustered in the Very Common (ge 1 in 10 patients) and Common (ge 1 in 100 to < 1 in 10 patients) tiers, based on clinical data documented by authorities such as the EMA and FDA. These effects most frequently involve three key system-organ classes:

  • Blood and Lymphatic System Disorders: The most notable effects are myelosuppression, including neutropenia, thrombocytopenia, and anemia.
  • Gastrointestinal Disorders: Common events include nausea, vomiting, diarrhea, and abdominal pain.
  • General Disorders and Administration Site Conditions: Fatigue, pyrexia (fever), and localized injection site reactions (erythema, pain) are frequently observed.

Serious Adverse Reactions and Safety Constraints

Regulatory labeling specifies reactions considered serious or clinically significant. These include Febrile Neutropenia, a severe infection risk associated with low white blood cell counts, and toxicities related to vital organs such as Hepatotoxicity (liver injury) and Renal Failure.

Certain safety patterns are documented, such as the observation that myelosuppression is often most pronounced during the first 1 to 2 cycles of therapy. Furthermore, specific safety constraints exist for certain patient populations: individuals with severe preexisting hepatic impairment are identified as having a higher risk of toxicity and require close monitoring. The official safety profile mandates frequent monitoring of complete blood counts, liver chemistries, and serum creatinine before and throughout the treatment course.

Overdose and Emergency Response

Azacitidine Overdose and When to Seek Help

Azacitidine is administered by a healthcare professional and is therefore unlikely to result in an accidental overdose. However, receiving a dose significantly higher than prescribed may increase the severity of expected side effects, particularly myelosuppression (severe reduction in blood cell counts).

Signs of a potential overdose have included pronounced gastrointestinal symptoms, such as diarrhea, nausea, and vomiting. In a clinical context, a single dose approximately four times the standard starting dose was associated with these symptoms, which resolved with supportive care.

When to Contact Emergency Services

Since azacitidine affects blood cell production, a critical overdose can lead to severe or life-threatening complications. Immediate medical attention is required if you experience any signs of serious toxicity, which may include:

  • Signs of severe infection: Fever of 100.4°F (38°C) or higher, chills, or other flu-like symptoms.
  • Signs of severe bleeding or bruising: Unexplained heavy bleeding, black or bloody stools, or pinpoint red spots (petechiae) on the skin.
  • Signs of acute renal issues or tumor lysis syndrome: Significant decrease in urine output, rapid weight gain, or swelling of the feet/legs.

There is no specific antidote for azacitidine overdose. Management consists of close monitoring of blood counts and laboratory values, and providing supportive medical care as needed.

Therapeutic Uses of Azacitidine

Azacitidine is a systemic therapeutic agent primarily used in hematology to treat a group of specific blood and bone marrow disorders. Its application focuses on disease modification and contributing to therapeutic support in specific high-risk patient groups.

This medicine is considered a relevant therapeutic option for key hematologic conditions, including higher-risk Myelodysplastic Syndromes (MDS), specific forms of Acute Myeloid Leukemia (AML), and Chronic Myelomonocytic Leukemia (CMML). It is often applied when intensive conventional treatment is not feasible, such as in certain elderly or co-morbid adult patients. The therapeutic objective is to support the management of the condition and assist in maintaining functional stability.

The treatment is applied to help manage symptoms related to severe deficiencies in blood cells, specifically anemia, neutropenia, and thrombocytopenia. This symptomatic support may help with maintaining stability and assist with managing symptoms related to blood cell deficiencies, which can include fatigue and the risk of infection or hemorrhage.

“The primary goal is to help patients cope more steadily with symptom fluctuations and support general well-being during symptomatic phases.”

Quick Fact: Relief for Chronic Blood Cell Deficiencies
Azacitidine supports patients by addressing the underlying cause of low blood counts, which contributes to easing the overall symptom load associated with anemia and infection risk.

Regulatory References

  1. European Medicines Agency overview of Vidaza

Eligibility and Restrictions for Use

Azacitidine use is strictly defined by regulatory authorities and is classified based on patient age, pre-existing conditions, and physiological status.

Populations for Whom Use is Allowed

  • Adult Patients: Eligible for treatment of specific myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML).
  • Pediatric Patients: Eligible only for specific indications, such as Juvenile Myelomonocytic Leukemia (JMML), in patients aged one month and older. Use for other pediatric conditions is not established.

Absolute Contraindications

Azacitidine must not be used in the following populations, as stated in regulatory labeling:

Contraindicated Status Population or Condition
Absolute Patients with known hypersensitivity to azacitidine or mannitol.
Absolute Patients with advanced malignant hepatic tumors.
Absolute Women who are breastfeeding (Lactation).
Absolute Pregnant women (Use is contraindicated due to the risk of Embryo-Fetal Toxicity).

Eligibility-Related Restrictions

  • Organ Function: Patients with renal impairment or severe pre-existing hepatic impairment require close monitoring for toxicity.
  • Cardiovascular Conditions: Regulatory documents advise caution when prescribing to patients with a history of severe congestive heart failure or clinically unstable cardiac disease.
  • Reproductive Potential: Both males and females of reproductive potential must use effective contraception during and for a specified time after treatment.

What should I know about interactions with other medicines?

Azacitidine Interactions with other medicines and products

Azacitidine, a pyrimidine nucleoside analog, is primarily used in the treatment of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Its risk of clinically significant drug interactions is generally considered low compared to many other chemotherapy agents, as it is rapidly metabolized by cytidine deaminase enzymes in the liver and blood and does not primarily rely on the cytochrome P450 (CYP) enzyme system for clearance.


Potential Considerations

Interaction Type Examples/Agents Clinical Relevance
Other Chemotherapy Cytarabine, Gemcitabine Potential for overlapping toxicities (e.g., myelosuppression); use with caution.
Immunosuppressants Cyclosporine, Tacrolimus Increased risk of infection/myelosuppression due to combined immune effects; close monitoring is advised.

It is essential to inform your healthcare provider of all prescription and non-prescription medicines, vitamins, herbal supplements, and over-the-counter products you are taking. While there are no established major drug-drug interactions that significantly alter Azacitidine pharmacokinetics, caution is always necessary, especially with agents that also cause bone marrow suppression (myelosuppression) or affect liver/kidney function. Patients should strictly adhere to the dosing schedule and report any new or worsening side effects immediately.

Mechanism of Action

Azacitidine functions as a nucleoside analog and a prodrug that requires cellular activation by uridine-cytidine kinase. Once metabolized and incorporated into the DNA strand during replication, it becomes a suicide substrate for DNA methyltransferase (DNMT) enzymes. This process results in the covalent binding and subsequent depletion of DNMT enzymes, reducing the cell's capacity for DNA methylation. The resultant DNA hypomethylation reverses the epigenetic silencing of certain genes, including those critical for cellular development. This epigenetic change directly influences hematopoietic progenitor cells in the bone marrow, promoting the necessary processes of cellular differentiation and maturation. This mechanism leads to a shift in hematopoietic activity and supports the development of mature blood components, representing the ultimate physiological consequence of its action.

Dosage and Administration Information

Azacitidine is administered via two distinct, non-interchangeable methods: a parenteral (injectable) form and an oral tablet form, each with separate official dosing schedules.

Administration and Dosing

Product Form Route & Standard Cycle Dose Schedule (Adults)
Injection (Lyophilized Powder) Subcutaneous (SC) or Intravenous (IV) on Days 1–7 of a 28-day cycle. Recommended starting dose is 75 mg/m² (Body Surface Area) daily.
Oral Tablet Oral (PO) once daily on Days 1–14 of a 28-day cycle, followed by a 14-day rest period. Recommended standard dose is 300 mg daily.

Procedural and Use Requirements

Treatment is generally continued for a minimum number of cycles (e.g., at least six for the injectable form) and for as long as the patient continues to benefit.

Administration Specifics

  • Tablet Intake: The oral tablets must be swallowed whole and should not be split, crushed, or chewed. They may be taken with or without food.
  • SC Injection: Injection sites (thigh, abdomen, upper arm) must be rotated. Doses exceeding 4 mL must be divided into two separate injections. The powder is required to be reconstituted with sterile water immediately before administration to form a suspension.

Special Instructions

  • Dose Adjustments: No initial dose adjustment is required for older adults or patients with mild-to-moderate renal or hepatic impairment. Subsequent dose reductions may be necessary if certain laboratory abnormalities (e.g., unexplained low serum bicarbonate or high BUN/creatinine) occur.
  • Missed Oral Dose: If a dose is missed, it should be taken as soon as possible on the same day. Patients are instructed not to take two doses on the same day to compensate for the missed dose.

Recent Clinical Evidence

Research evidence / Overview of Studies for Azacitidine


Evidence for Use in Higher-Risk Myelodysplastic Syndromes (HR-MDS)

Research has extensively explored Azacitidine in the study of higher-risk Myelodysplastic Syndromes (MDS). The primary research base comes from Randomized Controlled Trials (RCTs), which are a strong study design for assessing outcomes. These pivotal studies evaluated the medicine against other forms of care or best supportive care, allowing researchers to observe and measure outcomes in the different study groups over a defined period.

The studies primarily monitored outcomes related to Overall Survival (OS) and time to transformation into Acute Myeloid Leukemia (AML). In the key randomized trial, reports described the measured survival outcomes and the comparative findings between the Azacitidine group and the conventional care regimens group. A key focus of the research was also on outcomes related to systemic or functional imbalance, such as the need for blood transfusions, which was tracked as Red Blood Cell Transfusion Independence (RBC-TI).


Evidence for Use in Acute Myeloid Leukemia (AML)

Research exploring Azacitidine in Acute Myeloid Leukemia (AML) addresses two distinct areas: studies for its initial administration in specific older adults and studies for its administration after initial remission (maintenance setting).

Frontline Research for Older Adults Unsuitable for Intensive Treatment

Research examined the use of Azacitidine as a first-line therapy for older adults (generally age 65 and above) who were considered unsuitable for the more intensive forms of chemotherapy. A key randomized Phase 3 trial was conducted in this specific high-risk group. The key outcome was studied for Overall Survival (OS), and trial reports described patterns related to the survival rates that were measured in the Azacitidine group.

Maintenance Research Following Remission (Oral Formulation)

Studies utilizing the oral formulation of Azacitidine was evaluated in the post-remission maintenance setting. This evidence comes from a large, double-blind, placebo-controlled Phase 3 trial that primarily explored outcomes related to Overall Survival (OS) and relapse-free survival (RFS). It is important to understand that this research is specific to the oral formulation and its use only after initial remission has been achieved.


What Remains Uncertain in the Research

Despite the body of high-quality research, some areas still represent research gaps or limitations:

  • Long-term effects are not fully established, meaning research does not determine what happens years after the study period in a large population.
  • Data for certain groups remain insufficient, particularly for patients with co-existing significant health issues (comorbidities) that would have excluded them from participation in the primary randomized trials.

Frequently Asked Questions (FAQ)

Common questions about Azacitidine (FAQ)


Q: What should I expect in the first month of treatment with Azacitidine?

Official product information indicates that side effects, particularly low blood cell counts (myelosuppression) and gastrointestinal issues like nausea, are typically most frequent and noticeable during the first one to two cycles of therapy. These effects necessitate close monitoring of blood counts during therapy.

Q: What are the most frequent skin reactions mentioned with Azacitidine?

The most common skin reactions reported in regulatory documents include a general rash, itching (pruritus), and bruising (ecchymosis) or small red spots (petechiae). If receiving the injectable form, reactions at the injection site are also frequently observed.

Q: Does Azacitidine affect the immune system?

Regulatory information describes Azacitidine as suppressing blood cell formation, known as myelosuppression, which leads to lower white blood cell counts. This reduction in immune cells increases the risk of infection. Uncommon hypersensitivity reactions are also listed in official documents.

Q: Are there any common foods or drinks that should be avoided while on Azacitidine?

According to the official product information for the oral form, the tablets may be taken with or without food. Regulatory documents do not specify any particular foods or drinks that must be avoided during treatment.

Q: Can Azacitidine be taken with other types of vitamins or supplements?

The overall risk of major drug-drug interactions is generally considered low because of how the drug is metabolized. Official documents note the necessity of medical supervision when Azacitidine is used concurrently with other agents due to the potential for combined effects that could impact blood cell counts or organ function.

Q: What is the difference between Azacitidine given by injection and the oral form?

The two formulations, injectable and oral, are not interchangeable and are used for different clinical purposes. The injectable form is typically indicated as a first-line treatment for certain blood disorders. The oral form is commonly used for maintenance therapy after a patient has achieved initial remission.

Q: How is the effectiveness of Azacitidine treatment measured?

Effectiveness is measured by monitoring changes in the patient’s blood cell counts and bone marrow status. Official studies define treatment success using specific criteria, such as achieving a Complete Response (CR) or Partial Response (PR), which relate to the normalization of blood components and the reduction of abnormal cells.

Q: Can Azacitidine be used in combination with other anti-cancer drugs?

Yes, Azacitidine is indicated for use in combination with other anti-cancer drugs. For instance, official information describes its use with venetoclax for treating certain adults with newly diagnosed acute myeloid leukemia (AML).

Q: Are there any known long-term effects on the heart from Azacitidine?

Official documents include a warning regarding the use of the medicine in patients with a history of severe heart disease. Clinical studies have reported an increased incidence of cardiac events, meaning heart-related issues, with the use of Azacitidine.

Q: Are there specific monitoring tests required before starting Azacitidine?

Yes, regulatory guidelines require that specific blood tests be conducted before the first dose is administered. These tests include a complete blood count (CBC), liver function tests, and serum creatinine levels, which measure kidney function.

Q: What percentage of patients report gastrointestinal issues with Azacitidine?

Gastrointestinal issues are very common side effects. For example, in a key clinical trial, approximately 34% of patients reported constipation. Official documents classify other issues, like loss of appetite (anorexia), as a very common occurrence.

Q: Is Azacitidine generally considered a first-line or second-line treatment?

Azacitidine is indicated as a first-line therapy for certain patient populations. This includes individuals with higher-risk myelodysplastic syndromes (MDS) and specific older adults with newly diagnosed acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy.

Q: Can Azacitidine treatment be stopped abruptly?

Official product information details procedures for delaying or adjusting the dose based on monitoring of blood counts. Changes to the treatment plan, including discontinuation, are managed through medical supervision based on monitoring data.

Q: Is it normal to have changes in appetite during treatment?

Yes, changes in appetite are a very common occurrence. Loss of appetite, medically termed anorexia, is specifically listed as a very common side effect in official regulatory safety documents.

Q: Are there different brand names for Azacitidine?

Yes, the active ingredient Azacitidine is marketed under different brand names, depending on its specific formulation and the geographic region. Examples include Vidaza for the injectable form and Onureg for the oral form.

Q: Does Azacitidine treatment involve hair loss?

Yes, hair loss, known as alopecia, is listed in official safety documents as a common side effect associated with Azacitidine treatment.

Q: What precautions should be taken regarding exposure to sunlight during treatment?

Some individual clinical reports have noted phototoxic skin reactions, which means increased sensitivity to light. Management of this potential risk involves discussing specific sun precautions with the healthcare team.

Q: Why is Azacitidine given in cycles instead of continuously?

Azacitidine is administered in treatment cycles that include a planned rest period. This is necessary to allow blood cell counts, which are often lowered by the drug (myelosuppression), to recover before the next treatment phase begins. Dose and cycle timing are adjusted based on these blood counts.

How should Azacitidine be stored and disposed of?

How to Store and Dispose of Azacitidine?

Azacitidine is a cytotoxic medicine requiring specific storage and disposal protocols.

️ Storage Conditions

Product Form Temperature Range Stability Constraint
Unopened Vial (Powder) 20 C to 25 C (Controlled Room Temp) Store in original container.
Reconstituted Liquid 2 C to 8 C (Refrigerated) Do not freeze. Stability varies from 1 to 30 hours, depending on reconstitution method.

The product must be stored out of the sight and reach of children.

️ Disposal Requirements

Azacitidine is classified as a hazardous drug. Any unused portion from the single-dose vial must be discarded. Disposal of the medicine and all associated waste must follow local requirements for cytotoxic compounds. Do not dispose of the product via household waste or wastewater.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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