Standard Dosing for Azacitidine Injections in Myelodysplastic Syndromes (MDS)
Azacitidine (Vidaza) is given as a subcutaneous injection at 75 mg/m² daily for 7 days, followed by a 21-day rest period, repeating every 28 days. Treatment continues for at least 4 to 6 cycles, with adjustments based on blood counts and response.[1][2]
Dosing Adjustments for Hematologic Toxicity
If platelet counts drop below 50,000/µL or absolute neutrophil count (ANC) falls below 750/µL, hold the dose until recovery to baseline or better. For the first cycle, reduce by 50% if severe issues occur; subsequent cycles use a tiered reduction (e.g., 67% or 50% of full dose based on nadir counts). No dose for renal impairment unless severe.[1][2]
Use in Acute Myeloid Leukemia (AML)
For AML patients aged 75+ or with comorbidities unfit for intensive therapy, the schedule matches MDS: 75 mg/m² subcutaneously daily for 7 days every 28 days. FDA-approved in 2020 under accelerated approval for this indication.[1][3]
Administration Details
Inject subcutaneously into the upper arm, thigh, or abdomen. Rotate sites to avoid irritation. Reconstitute with sterile water (no preservatives), use within 45 minutes, and discard unused portions. Premedicate with antiemetics if nausea occurs.[1][2]
Differences from Intravenous or Oral Forms
Subcutaneous is preferred over IV for convenience (IV requires 15-30 minutes daily infusion). Oral azacitidine (Onureg) for AML maintenance is 300 mg daily for 14 days every 28 days—distinct from injectable schedules.[1][3]
Monitoring and Duration
Check complete blood counts weekly initially, then before each cycle. Continue indefinitely if benefiting, as responses may take 3-6 months. Discontinue if no response after 6 cycles.[1][2]
[1]: Vidaza Prescribing Information (FDA)
[2]: Azacitidine Clinical Pharmacology (Drugs.com)
[3]: Onureg vs Vidaza Comparison (Medscape)