Hydroxyurea
/api/v1/drug/hydroxyureaMechanism of action
Sourced from openFDAMechanism-of-action class: Ribonucleotide Reductase Inhibitors.
Indications
Sourced from openFDA- Hydroxyurea capsules, USP 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.ICD-10: C95.90
Contraindications
Sourced from openFDA- Hydroxyurea capsules is contraindicated in patients who have demonstrated a previous hypersensitivity to hydroxyurea or any other component of the formulation. • In patients who have demonstrated a previous hypersensitivity to hydroxyurea or any other component of its formulation.contraindicated
Dosage & administration
Sourced from openFDAIndividualize treatment based on tumor type, disease state, response to treatment, patient risk factors, and current clinical practice standards. (2.1) Renal impairment: Reduce the dose of hydroxyurea by 50% in patients with creatinine clearance less than 60 mL/min. ( 2.3 , 8.6, 12.3 ) 2.1 Dosing Information Hydroxyurea 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. Hydroxyurea is a cytotoxic drug. Follow applicable special handling and disposal procedures [ see References (15) ]. Swallow hydroxyurea capsule whole. Do NOT open, break, or chew capsules because hydroxyurea is a cytotoxic drug. Prophylactic administration of folic acid is recommended [ see Warnings and Precautions (5.8) ]. Monitor blood counts at least once a week during hydroxyurea therapy. Severe anemia must be corrected before initiating therapy with hydroxyurea.
Warnings & precautions
Sourced from openFDAMyelosuppression: 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. (5.1) Hemolytic anemia: Monitor blood counts throughout treatment. If hemolysis persists, discontinue Hydroxyurea. (5.2) Malignancies: Advise protection from sun exposure and monitor for secondary malignancies. ( 5.3) 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 hydroxyurea and initiate treatment if this occurs. (5.5) Live Vaccinations: Avoid live vaccine use in a patient taking hydroxyurea capsules. (5.6) 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 hydroxyurea capsules and implement treatment. (5.7) Radiation recall: Monitor for skin erythema in patients who previously received radiation and manage symptomatically. (5.8) 5.1 Myelosuppression s ion Hydroxyurea causes severe myelosuppression. Treatment with hydroxyurea 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.
Adverse reactions
Sourced from openFDA• 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) ] • Radiation recall [see Warnings and Precautions (5.8) ] • Macrocytosis [see Warnings and Precautions (5.9) ] • Pulmonary Toxicity [see Warnings and Precautions (5.10) ] Most common adverse reactions (≥30%) are hematological, gastrointestinal symptoms, and anorexia. (6) To report SUSPECTED ADVERSE REACTIONS, contact Leading Pharma, LLC at 1-844-740-7500 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Postmarketing Experience The following adverse reactions have been identified during post-approval use of hydroxyurea capsules. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency.
Use in specific populations
Sourced from openFDALactation: Advise women not to breastfeed. (8.2) Geriatric Use: Care should be taken in dose selection and may require a lower dose regimen and monitoring of renal function. (8.5) 8.1 Pregnancy Risk Summary Hydroxyurea capsules 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 hydroxyurea capsules 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/m 2 basis (see Data). Advise women of the potential risk to a fetus and to avoid becoming pregnant while being treated with hydroxyurea capsules. 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/m 2 basis.
Overdosage
Sourced from openFDAAcute mucocutaneous toxicity has been reported in patients receiving hydroxyurea at dosages several times the therapeutic dose. Soreness, violet erythema, edema on palms and soles followed by scaling of hands and feet, severe generalized hyperpigmentation of the skin, and stomatitis have also been observed.
Approval history
Sourced from openFDA- Dec 7, 1967NDANDA016295Waylis Therap
- Oct 16, 1998ANDAANDA075143Barr
- Feb 24, 1999ANDAANDA075340Ph Health
- Dec 21, 2017NDANDA208843Theravia
- Apr 8, 2020ANDAANDA213438Leading
- Mar 6, 2024ANDAANDA218021Qilu
- Apr 4, 2024NDANDA216593Nova Labs Ltd
FAERS reports
- 1Off Label Use2,11910%
- 2Fatigue1,5207.3%
- 3Sickle Cell Anaemia With Crisis1,4807.1%
- 4Diarrhoea1,3906.7%
- 5Nausea1,2916.2%
- 6Headache1,0545.1%
- 7Anaemia1,0325.0%
- 8Death1,0244.9%
- 9Haemoglobin Decreased9374.5%
- 10Pyrexia9184.4%
- 11Drug Ineffective8924.3%
- 12Pain8574.1%
- 13Product Dose Omission Issue8173.9%
- 14Dyspnoea8143.9%
- 15Pneumonia7603.7%
Literature
Recent PubMed references pinned to Hydroxyurea as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.
- Challenges and opportunities in hydroxyurea access and adherence for sickle cell disease patients at Komfo Anokye Teaching Hospital: Insights from healthcare providers.PloS one · 2026 · Mensah J, Marfo AFA, Opare-Addo MNA, et al.PMID 42213654DOI 10.1371/journal.pone.0347848
- Sustainment of Hydroxyurea Adherence in Patients With Sickle Cell Disease.JAMA network open · 2026 · Heitzer AM, Wooten Z, Luo G, et al.PMID 42090151DOI 10.1001/jamanetworkopen.2026.11257
- Efficacy of Ayurveda Regimen as an Adjunct to Hydroxyurea in Sickle Cell Disease: Protocol for a Prospective, Randomized, Open-Label, Blinded End Point Exploratory Study.JMIR research protocols · 2026 · Javed D, Rai AK, Bansal S, et al.PMID 42054235DOI 10.2196/79603
- Sickle cell disease in Jharkhand: A registry-based evaluation of disease burden and healthcare needs.The Indian journal of medical research · 2026 · Prasad A, Kumari A, Kumar K, et al.PMID 41934414DOI 10.25259/IJMR_1644_2025
- Clinical Practice Patterns for Discussing Hydroxyurea Initiation With Families of Children With Sickle Cell Disease.Pediatric blood & cancer · 2026 · Hildenbrand AK, Lang A, Hood AM, et al.PMID 41925091DOI 10.1002/1545-5017.70292
- Zileuton, 5-lipoxygenase blocker, modulates acute inflammatory response in Nile tilapia.Developmental and comparative immunology · 2026 · Carlino-Costa C, de Oliveira SL, Aracati MF, et al.PMID 41881179DOI 10.1016/j.dci.2026.105595
- The GLOBE Trial: Efficacy and Safety of L-Glutamine Plus Hydroxyurea Versus Hydroxyurea Alone in Sickle Cell Anemia - A Double-Blind, Randomized Study.Turkish journal of haematology : official journal of Turkish Society of Haematology · 2026 · Shakibazad N, Momenzadeh M, Amiri B, et al.PMID 41664386DOI 10.4274/tjh.galenos.2026.09709
- Inhibiting Arachidonate-5-lipoxygenase expression ameliorates osteoarthritis progression by suppressing ferroptosis via the JAK2/STAT3 signaling pathway.Free radical biology & medicine · 2026 · Zou F, Zhang K, Sun X, et al.PMID 41581577DOI 10.1016/j.freeradbiomed.2026.01.035
Clinical trials
The 10 most recently updated of 349 ClinicalTrials.gov registrations naming Hydroxyurea as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.
- Bomedemstat vs Hydroxyurea for Essential Thrombocythemia (MK-3543-007)Recruiting · Phase 3 · Interventional · 300 enrolled · Merck Sharp & Dohme LLCNCT06456346updated 2026-06-12
- A Phase 2 Study to Assess STP938 as a Monotherapy in Adults With High Risk Essential Thrombocythaemia - The VECTRA TrialRecruiting · Phase 2 · Interventional · 50 enrolled · Step Pharma, SASNCT06786234updated 2026-06-12
- A Study of Bomedemstat (IMG-7289/MK-3543) Compared to Best Available Therapy (BAT) in Participants With Essential Thrombocythemia and an Inadequate Response or Intolerance of Hydroxyurea (MK-3543-006)Recruiting · Phase 3 · Interventional · 340 enrolled · Merck Sharp & Dohme LLCNCT06079879updated 2026-06-12
- Study to Identify and Describe Predictive Factors for Thromboembolic Events in Patients With High-risk Polycythemia VeraActive not recruiting · Observational · 242 enrolled · Novartis PharmaceuticalsNCT05548062updated 2026-06-11
- A Study to Learn About Sickle Cell Disease In Adult PatientsCompleted · Observational · 98 enrolled · PfizerNCT05407805updated 2026-06-10
- Genetically Engineered Cells (CD83 CAR T Cells) for the Treatment of Relapsed or Refractory Acute Myeloid LeukemiaRecruiting · Phase 1 · Interventional · 26 enrolled · Roswell Park Cancer InstituteNCT06871410updated 2026-06-10
- Study of Two Doses of Crizanlizumab Versus Placebo in Adolescent and Adult Sickle Cell Disease PatientsActive not recruiting · Phase 3 · Interventional · 255 enrolled · Novartis PharmaceuticalsNCT03814746updated 2026-06-08
- A Phase 1/2 Study of CPI-0610 With and Without Ruxolitinib in Patients With Hematologic and Myeloproliferative MalignanciesCompleted · Phase 1 · Phase 2 · Interventional · 336 enrolled · Constellation PharmaceuticalsNCT02158858updated 2026-06-04
- A Clinical Trial of TQ05105 Tablets in the Treatment of Moderate and High Risk MyelofibrosisCompleted · Phase 2 · Interventional · 107 enrolled · Chia Tai Tianqing Pharmaceutical Group Co., Ltd.NCT05020652updated 2026-06-02
- Haploidentical Donor Hematopoietic Cell Transplant for Sickle Cell DiseaseNot yet recruiting · Phase 2 · Interventional · 45 enrolled · St. Jude Children's Research HospitalNCT07616154updated 2026-06-01
Frequently asked questions
- How does Hydroxyurea work?
- Mechanism-of-action class: Ribonucleotide Reductase Inhibitors.
- What is Hydroxyurea used for?
- According to FDA labeling, Hydroxyurea carries indications including: Hydroxyurea capsules, USP 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.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
- What class of drug is Hydroxyurea?
- Hydroxyurea is classified as Other antineoplastic agents, Antimetabolite, Ribonucleotide Reductase Inhibitors, Decreased DNA Integrity.
- What are the brand names for Hydroxyurea?
- Hydroxyurea is marketed under brand names including Droxia, Hydrea, Siklos, Xromi.
- What are the contraindications for Hydroxyurea?
- Hydroxyurea labeling lists contraindications including: Hydroxyurea capsules is contraindicated in patients who have demonstrated a previous hypersensitivity to hydroxyurea or any other component of the formulation. • In patients who have demonstrated a previous hypersensitivity to hydroxyurea or any other component of its formulation.. Always consult the full prescribing information and a clinician.
hydroxyurea is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.