Droxia Dosage

Procedures for proper handling and disposal of cytotoxic drugs should be considered. Several guidelines on this subject have been published.2-5

To minimize the risk of dermal exposure, always wear impervious gloves when handling bottles containing DROXIA capsules. DROXIA capsules should not be opened. Personnel should avoid exposure to crushed or opened capsules. If contact with crushed or opened capsules occurs, wash immediately and thoroughly. More information is available in the references listed below.

Dosage should be based on the patient’s actual or ideal weight, whichever is less. The initial dose of DROXIA is 15 mg/kg/day as a single dose. The patient’s blood count must be monitored every two weeks. (See WARNINGS.)

If blood counts are in an acceptable range*, the dose may be increased by 5 mg/kg/day every 12 weeks until a maximum tolerated dose (the highest dose that does not produce toxic** blood counts over 24 consecutive weeks), or 35 mg/kg/day, is reached.

If blood counts are between the acceptable range* and toxic**, the dose is not increased.

If blood counts are considered toxic**, DROXIA should be discontinued until hematologic recovery. Treatment may then be resumed after reducing the dose by 2.5 mg/kg/day from the dose associated with hematologic toxicity. DROXIA may then be titrated up or down, every 12 weeks in 2.5 mg/kg/day increments, until the patient is at a stable dose that does not result in hematologic toxicity for 24 weeks. Any dosage on which a patient develops hematologic toxicity twice should not be tried again.

          *acceptable range =
                    neutrophils ≥2500 cells/mm3,
                    platelets ≥95,000/mm3,
                    hemoglobin >5.3 g/dL and
                    reticulocytes ≥95,000/mm3 if the hemoglobin concentration <9 g/dL.

          **toxic =
                    neutrophils <2000 cells/mm3,
                    platelets <80,000/mm3,
                    hemoglobin <4.5 g/dL and
                    reticulocytes <80,000/mm3 if the hemoglobin concentration <9 g/dL.

Since hydroxyurea may raise the serum uric acid level, dosage adjustment of uricosuric medication may be necessary.