HYDREA (hydroxyurea capsules, USP) is an antimetabolite available for oral use as capsules containing 500 mg hydroxyurea. Inactive ingredients include citric acid, colorants (D&C Yellow No. 10, FD&C Blue No. 1, FD&C Red No. 40, and D&C Red No. 28), gelatin, lactose, magnesium stearate, sodium phosphate, and titanium dioxide. Hydroxyurea is a white to off-white crystalline powder. It is hygroscopic and freely soluble in water, but practically insoluble in alcohol. The empirical formula is CH ​ 4 N 2 O 2 and it has a molecular weight of 76.05. Its structural formula is: Hydroxyurea Chemical Structure

HYDREA is indicated for the treatment of: • Resistant chronic myeloid leukemia. • Locally advanced squamous cell carcinomas of the head and neck (excluding the lip) in combination with chemoradiation. HYDREA is an antimetabolite indicated for the treatment of: Resistant chronic myeloid leukemia. Locally advanced squamous cell carcinomas of the head and neck, (excluding lip) in combination with concurrent chemoradiation.

Capsules: 500 mg opaque green cap and opaque pink body imprinted with "HYDREA" and "500". Capsules: 500 mg

Individualize treatment based on tumor type, disease state, response to treatment, patient risk factors, and current clinical practice standards. Renal impairment: Reduce the dose of HYDREA by 50% in patients with creatinine clearance less than 60 mL/min. (2.3 , 8.6 , 12.3) 2.1 Dosing Information HYDREA is used alone or in conjunction with other antitumor agents or radiation therapy to treat neoplastic diseases. Individualize treatment based on tumor type, disease state, response to treatment, patient risk factors, and current clinical practice standards. Base all dosage on the patient's actual or ideal weight, whichever is less. HYDREA is a cytotoxic drug. Follow applicable special handling and disposal procedures . Swallow HYDREA capsules whole. Do NOT open, break, or chew capsules because HYDREA is a cytotoxic drug. Prophylactic administration of folic acid is recommended . Monitor blood counts at least once a week during HYDREA therapy. Severe anemia must be corrected before initiating therapy with HYDREA

Dose Modifications for Toxicity Monitor for the following and reduce the dose or discontinue HYDREA accordingly: Myelosuppression [ see Warnings and Precautions ] Cutaneous vasculitis [ see Warnings and Precautions ] Consider dose modifications for other toxicities

Dose Modifications for Renal Impairment Reduce the dose of HYDREA by 50% in patients with measured creatinine clearance of less than 60 mL/min or with end-stage renal disease (ESRD) [ see Use in Specific Populations and Clinical Pharmacology ]. Creatinine Clearance (mL/min) Recommended HYDREA Initial Dose (mg/kg once daily) ≥60 15 <60 or ESRD* 7.5 * On dialysis days, administer HYDREA to patients following hemodialysis. Close monitoring of hematologic parameters is advised in these patients.

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. Hemolytic anemia: Monitor blood counts throughout treatment. If hemolysis persists, discontinue HYDREA. Malignancies: Advise protection from sun exposure and monitor for secondary malignancies. Embryo-Fetal toxicity: Can cause fetal harm. Advise of potential risk to a fetus and use of effective contraception. ( 5.4 , 8.1 , 8.3) Vasculitic toxicities: Discontinue HYDREA and initiate treatment if this occurs. Live Vaccinations: Avoid live vaccine use in a patient taking HYDREA. Risks with concomitant use of antiretroviral drugs: Pancreatitis, hepatotoxicity, and neuropathy have occurred. Monitor for signs and symptoms in patients with HIV infection using antiretroviral drugs; discontinue HYDREA and implement treatment. Radiation recall: Monitor for skin erythema in patients who previously received radiation and manage symptomatically. 5.1 Myelosuppression Hydroxyurea causes severe myelosuppression. Treatment with HYDREA 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. Bone marrow depression is more likely in patients who have previously received radiotherapy or cytotoxic cancer chemotherapeutic agents; use HYDREA cautiously in such patients. Evaluate hematologic status prior to and during treatment with HYDREA. Provide supportive care and modify dose or discontinue HYDREA as needed. Recovery from myelosuppression is usually rapid when therapy is interrupted

Hemolytic Anemia Cases of hemolytic anemia in patients treated with HYDREA for myeloproliferative diseases have been reported . 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 HYDREA

Malignancies Hydroxyurea is a human carcinogen. In patients receiving long-term hydroxyurea for myeloproliferative disorders, secondary leukemia has been reported. 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, HYDREA 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/m 2 basis. Advise pregnant women of the potential risk to a fetus . Advise females of reproductive potential to use effective contraception during and after treatment with HYDREA for at least 6 months after therapy. Advise males of reproductive potential to use effective contraception during and after treatment with HYDREA for at least 1 year after therapy

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 HYDREA

Live Vaccinations Avoid use of live vaccine in patients taking HYDREA. Concomitant use of HYDREA 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 HYDREA. Vaccination with live vaccines in a patient receiving HYDREA 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

Radiation Recall Patients who have received irradiation therapy in the past may have an exacerbation of post-irradiation erythema. Monitor for skin erythema in patients who previously received radiation and manage symptomatically

Macrocytosis HYDREA 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 B 12 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. Monitor patients developing pyrexia, cough, dyspnea, or other respiratory symptoms frequently, investigate and treat promptly. Discontinue HYDREA and manage with corticosteroids

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 . 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 .

Antiretroviral drugs Laboratory Test Interference

Increased Toxicity with Concomitant Use of Antiretroviral Drugs Pancreatitis In patients with HIV infection during therapy with hydroxyurea and didanosine, with or without stavudine, fatal and nonfatal pancreatitis have occurred. Hydroxyurea is not indicated for the treatment of HIV infection; however, if patients with HIV infection are treated with hydroxyurea, and in particular, in combination with didanosine and/or stavudine, close monitoring for signs and symptoms of pancreatitis is recommended. Permanently discontinue therapy with HYDREA in patients who develop signs and symptoms of pancreatitis. Hepatotoxicity Hepatotoxicity and hepatic failure resulting in death have been reported during postmarketing surveillance in patients with HIV infection treated with hydroxyurea and other antiretroviral drugs. Fatal hepatic events were reported most often in patients treated with the combination of hydroxyurea, didanosine, and stavudine. Avoid this combination. Peripheral Neuropathy Peripheral neuropathy, which was severe in some cases, has been reported in patients with HIV infection receiving hydroxyurea in combination with antiretroviral drugs, including didanosine, with or without stavudine

Laboratory Test Interference Interference with Uric Acid, Urea, or Lactic Acid Assays Studies have shown that there is an analytical interference of hydroxyurea with the enzymes (urease, uricase, and lactate dehydrogenase) used in the determination of urea, uric acid, and lactic acid, rendering falsely elevated results of these in patients treated with hydroxyurea. Interference with Continuous Glucose Monitoring Systems 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 CGM is to be prescribed hydroxyurea, consult with the CGM prescriber about alternative glucose monitoring methods.