Droxia

— THERAPEUTIC CATEGORIES —
  • Anemias

Droxia Generic Name & Formulations

General Description

Hydroxyurea 200mg, 300mg, 400mg; caps.

Pharmacological Class

Antimetabolite.

How Supplied

Caps—60

Manufacturer

Generic Availability

NO

Mechanism of Action

The mechanisms by which hydroxyurea produces its beneficial effects in those with sickle cell anemia are uncertain. Known pharmacologic effects of hydroxyurea that may contribute to its beneficial effects include increasing hemoglobin F levels in red blood cells (RBCs), decreasing neutrophils, increasing the water content of RBCs, increasing deformability of sickled cells, and altering the adhesion of RBCs to endothelium.

Droxia Indications

Indications

To reduce the frequency of painful crises and to reduce the need for blood transfusions in adults with sickle cell anemia with recurrent moderate to severe painful crises.

Droxia Dosage and Administration

Adult

Swallow whole. Base dose on ideal or actual weight, whichever is less. Initially 15mg/kg/day as a single dose. May increase dose by 5mg/kg/day every 12 weeks to maximum tolerated dose or 35mg/kg/day achieved; do not increase dose if blood counts are between acceptable and toxic range. If blood counts toxic, discontinue until hematologic recovery, see full labeling for dosage adjustments. Renal impairment (CrCl <60mL/min or ESRD): initially 7.5mg/kg/day; give dose following dialysis (monitor).

Children

Not established.

Droxia Contraindications

Not Applicable

Droxia Boxed Warnings

Boxed Warning

Myelosuppression. Malignancies.

Droxia Warnings/Precautions

Warnings/Precautions

Risk of severe myelosuppression. Markedly depressed bone marrow function: do not initiate. Monitor CBCs prior to and during therapy; interrupt, reduce dose, or discontinue as needed. Discontinue if confirmed diagnosis of hemolytic anemia. Monitor for secondary malignancies (eg, leukemia, skin cancer). Avoid sun exposure. Macrocytosis may mask folic acid deficiency; prophylactic folic acid is recommended. Pulmonary toxicity (monitor). Myeloproliferative disorders; discontinue if cutaneous vasculitic ulcerations occur. Obtain fetal hemoglobin (HbF) levels every 3–4 months; may be used to assess efficacy. Renal or hepatic impairment. Elderly. Embryo-fetal toxicity. Advise to use effective contraception during and for ≥6 months (females of reproductive potential) or ≥1 year (males) after therapy. Pregnancy: exclude status prior to initiation. Nursing mothers: not recommended.

Droxia Pharmacokinetics

Absorption

Peak plasma concentrations are reached in 1–4 hours.

Distribution

Distributed throughout the body with a volume of distribution approximating total body water.

Metabolism

Up to 60% of an oral dose undergoes conversion through saturable hepatic metabolism and a minor pathway of degradation by urease found in intestinal bacteria.

Elimination

Renal (40%).

Droxia Interactions

Interactions

Avoid concomitant didanosine, with or without stavudine, or other antiretrovirals (may cause pancreatitis [monitor], fatal hepatotoxicity, peripheral neuropathy). Avoid live vaccines. Increased risk of vasculitic toxicities with interferon therapy. May cause falsely elevated results in urea, uric acid, and lactic acid assays. May falsely elevate sensor glucose results from certain continuous glucose monitoring (CGM) systems leading to hypoglycemia, if results are relied upon to dose insulin.

Droxia Adverse Reactions

Adverse Reactions

Leukopenia, thrombocytopenia, anemia, neutropenia, GI upset, anorexia, hair loss, macrocytosis, bleeding, melanonychia; interstitial lung disease.

Droxia Clinical Trials

See Literature

Droxia Note

Notes

Wear disposable gloves when handling caps or bottle.

Droxia Patient Counseling

See Literature