The dosage of Ruxolitinib should be adjusted according to the indications, patient platelet count, and treatment response. The whole tablet should be swallowed and blood routine and liver function should be monitored regularly.

1 Standard Dose Protocol

(1) Bone marrow fibrosis: The initial dose is based on platelet count. When the platelet count is ≥ 200 × 10 ⁹/L, 20mg each time twice a day; When the platelet count is 100-200 × 10 ⁹/L, take 15mg twice a day each time.

(2) Polycythemia vera: The initial dose is 10mg twice daily, adjusted based on efficacy and tolerability.

(3) Graft-versus-host disease: The dosage should be calculated based on body weight, usually 5-10mg twice a day.

Principle of dose adjustment

(1) Thrombocytopenia: If the platelet count is less than 50 × 10 ⁹/L, the medication should be suspended and reduced before resuming.

(2) Anemia worsens: When hemoglobin is less than 8g/dL, treatment needs to be interrupted and blood transfusion support may be necessary.

(3) Abnormal liver function: Patients with moderate to severe liver damage need to reduce their dosage by 50%, and Child Pugh C grade should be avoided.

3 Medication precautions

(1) Usage: Swallow the whole tablet and do not break it open. It can be taken with food or on an empty stomach.

(2) Time interval: The interval between two doses is about 12 hours. If the missed dose exceeds 4 hours, the dose should be skipped.

(3) Drug interactions: Strong CYP3A4 inhibitors need to be reduced by 50%, and inducers may decrease efficacy.

4. Medication for special populations

(1) Elderly patients: No need to adjust dosage, but close monitoring of adverse reactions is required.

(2) Renal insufficiency: Mild to moderate without adjustment, use with caution in patients with end-stage renal disease.

(3) Pregnant breastfeeding: Prohibited during pregnancy, stop breastfeeding during treatment and within 2 weeks after discontinuation of medication.