Indication & Safety Information for DROXIA®
DROXIA is indicated to reduce the frequency of painful crises and to reduce the need for blood transfusions in patients with sickle cell anemia with recurrent moderate to severe painful crises.
CONTRAINDICATIONS
DROXIA is contraindicated in patients who have demonstrated a previous hypersensitivity to hydroxyurea or any other component of its formulation.
ADVERSE REACTIONS
Most common adverse reactions (≥30%) are hematological, gastrointestinal symptoms, and anorexia. (6)
To report SUSPECTED ADVERSE REACTIONS, contact the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
IMPORTANT SAFETY INFORMATION AND INDICATIONS
INDICATIONS AND USAGE
DROXIA is indicated to reduce the frequency of painful crises and to reduce the need for blood transfusions in patients with sickle cell anemia with recurrent moderate to severe painful crises.
INDICATIONS AND USAGE
WARNING: MYELOSUPPRESSION AND MALIGNANCIES
Myelosuppression: DROXIA may cause severe myelosuppression. Do not give if bone marrow function is markedly depressed. Monitor blood counts at baseline and throughout treatment. Interrupt treatment and reduce dose as necessary [see Warnings and Precautions].
Malignancies: DROXIA is carcinogenic. Advise sun protection and monitor patients for malignancies [see Warnings and Precautions].
CONTRAINDICATIONS
DROXIA is contraindicated in patients who have demonstrated a previous hypersensitivity to hydroxyurea or any other component of its formulation.
WARNINGS AND PRECAUTIONS
Myelosuppression
Hydroxyurea causes severe myelosuppression. Treatment with DROXIA should not be initiated if bone marrow function is markedly depressed. Bone marrow suppression may occur, and leukopenia is generally its first and most common manifestation. Thrombocytopenia and anemia occur less often and are seldom seen without a preceding leukopenia.
Some patients, treated at the recommended initial dose of 15 mg/kg/day, have experienced severe or life-threatening myelosuppression.
Evaluate hematologic status prior to and during treatment with DROXIA. Provide supportive care and modify dose or discontinue DROXIA as needed. Recovery from myelosuppression is usually rapid when therapy is interrupted.
Hemolytic Anemia
Cases of hemolytic anemia in patients treated with hydroxyurea for myeloproliferative diseases have been reported [see Adverse Reactions (6.1)]. Patients who develop acute jaundice or hematuria in the presence of persistent or worsening of anemia should have laboratory tests evaluated for hemolysis (e.g., measurement of serum lactate dehydrogenase, haptoglobin, reticulocyte, unconjugated bilirubin levels, urinalysis, and direct and indirect antiglobulin [Coombs] tests). In the setting of confirmed diagnosis of hemolytic anemia and in the absence of other causes, discontinue DROXIA.
Malignancies
Hydroxyurea is a human carcinogen. In patients receiving long-term hydroxyurea for myeloproliferative disorders, secondary leukemia has been reported.
Secondary leukemia has also been reported in patients treated with long-term hydroxyurea for sickle cell disease. Leukemia has also been reported in patients with sickle cell disease and no prior history of treatment with hydroxyurea.
All patients using DROXIA should be followed up on a long-term basis with regular blood counts to detect development of leukemia.
Skin cancer has also been reported in patients receiving long-term hydroxyurea. Advise protection from sun exposure and monitor for the development of secondary malignancies.
Embryo-Fetal Toxicity
Based on the mechanism of action and findings in animals, DROXIA can cause fetal harm when administered to a pregnant woman. Hydroxyurea was embryotoxic and teratogenic in rats and rabbits at doses 0.8 times and 0.3 times, respectively, the maximum recommended human daily dose on a mg/m2 basis. Advise pregnant women of the potential risk to a fetus [see Use in Specific Populations (8.1)].
Advise females of reproductive potential to use effective contraception during and after treatment with DROXIA for at least 6 months after therapy. Advise males of reproductive potential to use effective contraception during and after treatment with DROXIA for at least 1 year after therapy [see Use in Specific Populations (8.1, 8.3)].
Vasculitic Toxicities
Cutaneous vasculitic toxicities, including vasculitic ulcerations and gangrene, have occurred in patients with myeloproliferative disorders during therapy with hydroxyurea. These vasculitic toxicities were reported most often in patients with a history of, or currently receiving, interferon therapy. If cutaneous vasculitic ulcers occur, institute treatment and discontinue DROXIA.
Live Vaccinations
Avoid use of live vaccine in patients taking DROXIA. Concomitant use of DROXIA with a live virus vaccine may potentiate the replication of the virus and/or may increase the adverse reaction of the vaccine because normal defense mechanisms may be suppressed by DROXIA. Vaccination with live vaccines in a patient receiving DROXIA may result in severe infection. Patient's antibody response to vaccines may be decreased. Consider consultation with a specialist.
Risks with Concomitant Use of Antiretroviral Drugs
Pancreatitis, hepatotoxicity, and peripheral neuropathy have occurred when hydroxyurea was administered concomitantly with antiretroviral drugs, including didanosine and stavudine [see Drug Interactions (7.1)].
Macrocytosis
DROXIA may cause macrocytosis, which is self-limiting, and is often seen early in the course of treatment. The morphologic change resembles pernicious anemia, but is not related to vitamin B12 or folic acid deficiency. This may mask the diagnosis of pernicious anemia. Prophylactic administration of folic acid is recommended.
Pulmonary Toxicity
Interstitial lung disease including pulmonary fibrosis, lung infiltration, pneumonitis, and alveolitis/allergic alveolitis (including fatal cases) have been reported in patients treated for myeloproliferative neoplasm. Safety and effectiveness have not been established for the use of DROXIA in the treatment of myeloproliferative neoplasms and the use is not approved by the FDA. Monitor patients developing pyrexia, cough, dyspnea, or other respiratory symptoms frequently, investigate and treat promptly. Discontinue DROXIA and manage with corticosteroids. [see Adverse Reactions (6.1)].
Laboratory Test Interference
Interference with Uric Acid, Urea, or Lactic Acid Assays is possible, rendering falsely elevated results of these in patients treated with hydroxyurea [see Drug Interactions (7.2)].
Hydroxyurea may falsely elevate sensor glucose results from certain continuous glucose monitoring (CGM) systems and may lead to hypoglycemia if sensor glucose results are relied upon to dose insulin.
If a patient using a CGM is to be prescribed hydroxyurea, consult with the CGM prescriber about alternative glucose monitoring methods [see Drug Interactions (7.2)].
ADVERSE REACTIONS
The following clinically significant adverse reactions are described in detail in other labeling sections:
- Myelosuppression [see Warnings and Precautions (5.1)]
- Hemolytic anemia [see Warnings and Precautions (5.2)]
- Malignancies [see Warnings and Precautions (5.3)]
- Vasculitic toxicities [see Warnings and Precautions (5.5)]
- Risks with concomitant use of antiretroviral drugs [see Warnings and Precautions (5.7)]
- Macrocytosis [see Warnings and Precautions (5.8)]
- Pulmonary Toxicity [see Warnings and Precautions (5.9)]
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Clinical Trial Experience
In 299 patients treated for sickle cell anemia in the Multicenter Study of Hydroxyurea in Sickle Cell Anemia, the most common adverse reactions were hematologic, with neutropenia, and low reticulocyte and platelet levels necessitating temporary cessation in almost all patients. Hematologic recovery usually occurred in two weeks.
Other adverse reactions include hair loss, macrocytosis, bleeding, and melanonychia.
Postmarketing Experience
The following adverse reactions have been identified during post-approval use of hydroxyurea in the treatment of neoplastic diseases. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency.
- Reproductive System and Breast disorders: azoospermia, and oligospermia
- Gastrointestinal disorders: stomatitis, nausea, vomiting, diarrhea, and constipation
- Metabolism and Nutrition disorders: anorexia
- Skin and subcutaneous tissue disorders: maculopapular rash, skin ulceration, cutaneous lupus erythematosus, dermatomyositis-like skin changes, peripheral and facial erythema, hyperpigmentation, nail hyperpigmentation, atrophy of skin and nails, scaling, violet papules, and alopecia
- Renal and urinary disorders: dysuria, elevations in serum uric acid, blood urea nitrogen (BUN), and creatinine levels
- Nervous system disorders: headache, dizziness, drowsiness, disorientation, hallucinations, and convulsions
- General disorders: fever, chills, malaise, edema, and asthenia
- Hepatobiliary disorders: elevation of hepatic enzymes, cholestasis, and hepatitis
- Respiratory disorders: diffuse pulmonary infiltrates, dyspnea, and pulmonary fibrosis, interstitial lung disease, pneumonitis, alveolitis, allergic alveolitis and cough
- Immune disorders: systemic lupus erythematosus
- Hypersensitivity: Drug-induced fever (pyrexia) (>39°C, >102°F) requiring hospitalization has been reported concurrently with gastrointestinal, pulmonary, musculoskeletal, hepatobiliary, dermatological or cardiovascular manifestations. Onset typically occurred within 6 weeks of initiation and resolved upon discontinuation of hydroxyurea. Upon re-administration fever re-occurred typically within 24 hours.
- Blood and lymphatic system disorders: hemolytic anemia
To report SUSPECTED ADVERSE REACTIONS, contact the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
USE IN SPECIFIC POPULATIONS
Pregnancy
Risk Summary
DROXIA can cause fetal harm based on findings from animal studies and the drug's mechanism of action [see Clinical Pharmacology (12.1)]. There are no data with DROXIA use in pregnant women to inform a drug-associated risk. In animal reproduction studies, administration of hydroxyurea to pregnant rats and rabbits during organogenesis produced embryotoxic and teratogenic effects at doses 0.8 times and 0.3 times, respectively, the maximum recommended human daily dose on a mg/m2 basis (see Data). Advise women of the potential risk to a fetus and to avoid becoming pregnant while being treated with DROXIA.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%–4% and 15%–20%, respectively.
Data
Animal Data
Hydroxyurea has been demonstrated to be a potent teratogen in a wide variety of animal models, including mice, hamsters, cats, miniature swine, dogs, and monkeys at doses within 1-fold of the human dose given on a mg/m2 basis. Hydroxyurea is embryotoxic and causes fetal malformations (partially ossified cranial bones, absence of eye sockets, hydrocephaly, bipartite sternebrae, missing lumbar vertebrae) at 180 mg/kg/day (about 0.8 times the maximum recommended human daily dose on a mg/m2 basis) in rats and at 30 mg/kg/day (about 0.3 times the maximum recommended human daily dose on a mg/m2 basis) in rabbits. Embryotoxicity was characterized by decreased fetal viability, reduced live litter sizes, and developmental delays. Hydroxyurea crosses the placenta. Single doses of ≥375 mg/kg (about 1.7 times the maximum recommended human daily dose on a mg/m2 basis) to rats caused growth retardation and impaired learning ability.
Lactation
Risk Summary
Hydroxyurea is excreted in human milk. Because of the potential for serious adverse reactions in a breastfed infant from hydroxyurea, including carcinogenicity, discontinue breastfeeding during treatment with DROXIA.
Females and Males of Reproductive Potential
Pregnancy Testing
Verify the pregnancy status of females of reproductive potential prior to initiating DROXIA therapy.
Contraception
Females
DROXIA can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1)]. Advise females of reproductive potential to use effective contraception during and after treatment with DROXIA for at least 6 months after therapy. Advise females to immediately report pregnancy.
Males
DROXIA may damage spermatozoa and testicular tissue, resulting in possible genetic abnormalities. Males with female sexual partners of reproductive potential should use effective contraception during and after treatment with DROXIA for at least 1 year after therapy [see Nonclinical Toxicology (13.1)].
Infertility
Males
Based on findings in animals and humans, male fertility may be compromised by treatment with DROXIA. Azoospermia or oligospermia, sometimes reversible, has been observed in men. Inform male patients about the possibility of sperm conservation before the start of therapy [see Adverse Reactions (6) and Nonclinical Toxicology (13.1)].
Pediatric Use
Safety and effectiveness in pediatric patients have not been established.
Geriatric Use
Clinical studies of DROXIA did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Elderly patients may be more sensitive to the effects of hydroxyurea and may require a lower dose regimen. Hydroxyurea is excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function [see Dosage and Administration (2.2)].
Renal Impairment
The exposure to hydroxyurea is higher in patients with creatinine clearance of less than 60 mL/min. Reduce dosage and closely monitor the hematologic parameters when DROXIA is to be administered to these patients [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3)].
Hepatic Impairment
There are no data that support specific guidance for dosage adjustment in patients with hepatic impairment. Close monitoring of hematologic parameters is advised in these patients.
PATIENT COUNSELING INFORMATION
Advise the patient to read the FDA-approved patient labeling (Medication Guide).
- There is a risk of myelosuppression. Monitoring blood counts every two weeks throughout the duration of therapy should be emphasized to patients taking DROXIA. Advise patients to report signs and symptoms of infection or bleeding immediately [see Warnings and Precautions (5.1)].
- Advise patients of the risk of hemolytic anemia. Advise patients that they will have blood tests to evaluate for this if they develop persistent anemia. [see Warnings and Precautions (5.2)].
- Advise patients that there is a risk of cutaneous vasculitic toxicities and secondary malignancies including leukemia and skin cancers. Advise use of sun protection [see Warnings and Precautions (5.3, 5.5)].
- Advise patients to inform their healthcare provider if they have received or are planning to receive vaccinations while taking DROXIA as this may result in a severe infection [see Warnings and Precautions (5.6)].
- Advise patients to notify their healthcare provider if they are using a continuous glucose monitoring system while taking DROXIA [see Warnings and Precautions (5.10)].
- Advise females of reproductive potential of the potential risk to a fetus and to inform their healthcare provider of a known or suspected pregnancy. Advise females and males of reproductive potential to use contraception during and after treatment with DROXIA [see Warnings and Precautions (5.4) and Use in Specific Populations (8.1, 8.3)].
- Advise females to discontinue breastfeeding during treatment with DROXIA [see Use in Specific Populations (8.2)].
- Patients with HIV infection should contact their physician for signs and symptoms of pancreatitis, hepatic events, and peripheral neuropathy [see Warnings and Precautions (5.7)].
- Advise patients of the symptoms of potential pulmonary toxicity and instruct them to seek prompt medical attention in the event of pyrexia, cough, dyspnea, or other respiratory symptoms [see Warnings and Precautions (5.9)].