skip to content
Primary navigation


DrugSiklos® (hydroxyurea) [Medunik]

April 2019

Therapeutic Area - Sickle cell anemia

Approval criteria

  • Patient has diagnosis of sickle cell anemia with recurrent moderate to severe painful crises AND
  • Patient is ≥ 2 years of age AND
  • Patient does NOT have a myeloproliferative disorder (for which Siklos is not approved) AND
  • Negative pregnancy status in female patients prior to starting Siklos therapy AND
  • Patient (female and male) attest to use of effective contraception during therapy, and for ≥ 6 months after discontinuation of Siklos AND
  • Patient has adequate functioning bone marrow at start of therapy as indicated by:
    • Absolute neutrophil count (ANC) ≥ 1,250/mm3 AND
    • Platelet count ≥ 80,000 mm3 AND
    • Hemoglobin (Hb) ≥ 4.5 g/dL AND
    • Reticulocyte count ≥ 80,000 mm3 if Hb < 9 g/dL AND
  • The patient’s blood counts will be monitored at baseline and every 2 weeks during therapy AND
  • Prescriber attests to patient counseling regarding sun protection and will monitor for malignancies

Quantity limits

  • 35 mg/kg/day; and patient’s most current weight must be provided at time of request
  • Calculate the rounded doses to the nearest 50 mg or 100 mg strength; and provide clinical rationale for rounding dosages taking into consideration that Siklos 100 mg tablets cannot be split; and Siklos 1000 mg tablets can be split into four 250 mg parts


Siklos is an antimetabolite, FDA-approved to reduce the frequency of painful crises and to reduce the need for blood transfusions in pediatric patients, 2 years of age and older, with sickle cell anemia with recurrent moderate to severe painful crises.


MHCP Provider Call Center 651-431-2700 or 800-366-5411

back to top