Hydroxycarbamide (Hydroxyurea)
Pronunciation: (ZROH-mee).
- Generic name
- Hydroxycarbamide (hydroxyurea)
- Brand names
- Hydrea, Xromi, Cytodrox, Droxia, Hydrostat, Myelostat
- Drug class
- Ribonucleotide reductase inhibitor; disease-modifying agent for sickle cell disease (this specific Xromi oral-solution product). The same molecule, hydroxycarbamide/hydroxyurea, is also used as an antineoplastic (cancer) agent in other capsule/tablet products under different brand names — see brand_names_note.
Availability and supply rules vary by country
Trade names by country: India
Australia: · Full directory
What Hydroxycarbamide (hydroxyurea) is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Hydroxycarbamide (hydroxyurea) works
Mechanism-of-action detail beyond the recorded indications and dosing above was not captured as a separate field in the clinician-authored database record for this medicine; see how_to_take and professional_information.regional_dosing for the recorded clinical detail. (2)
What Hydroxycarbamide (hydroxyurea) is used for
Prevention of vaso-occlusive complications of sickle cell disease (patients over 9 months of age)
This is Xromi's sole approved indication, per the UK/EU-approved product information for this specific oral-solution brand. Note: the clinician-authored database record also listed chronic myeloid leukaemia, polycythemia vera, and essential thrombocythemia — these are indications for other hydroxycarbamide/hydroxyurea capsule products (e.g., Hydrea, Droxia) under different brand names, not for the Xromi oral solution, and have been removed from this page's approved-use list as a correction. (2) (1)
Before taking Hydroxycarbamide (hydroxyurea)
Do not take / not appropriate for
- hypersensitivity to hydroxycarbamide or excipients. (Contraindication) (1)
- severe hepatic impairment (Child-Pugh C). (Contraindication) (1)
- severe renal impairment (creatinine clearance <30 mL/min). (Contraindication) (1)
- toxic-range myelosuppression. (Contraindication) (1)
- pregnancy and breastfeeding. (Contraindication) (1)
- concomitant antiretroviral medicines for HIV. (Contraindication) (1)
Tell your clinician about
(1)How to take Hydroxycarbamide (hydroxyurea)
- Take Xromi exactly as prescribed by your doctor. Any change to your dose, including stopping treatment, must be made by your prescriber. Take the oral solution by mouth using the dosing syringe provided (a 3 mL syringe for doses of 3 mL or less, a 10 mL syringe for larger doses) — do not use a kitchen spoon. It may be taken with or after meals, but use the same method each time, and drink water after each dose. Dosing is weight-based and individually titrated by your prescriber: starting dose 15 mg/kg/day, increased by 5 mg/kg/day about every 8 weeks until a mildly myelosuppressive dose is reached, usual maintenance 20-25 mg/kg/day, maximum 35 mg/kg/day. A clinical response can take 3-6 months to become apparent.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
The product information for Xromi does not give specific missed-dose guidance. If you miss a dose, contact your prescriber or pharmacist for advice on your next dose rather than deciding on your own whether to take, skip, or double it.
Overdose
In case of overdose, seek emergency medical attention immediately. The product information describes overdose symptoms as mucocutaneous toxicity — soreness with redness, swelling of the palms and soles, skin hyperpigmentation, and mouth sores (stomatitis) — alongside the general risk of severe bone marrow suppression, infection, or bleeding. Treatment (gastric lavage followed by supportive therapy, with monitoring of vital signs, blood/urine chemistry, and blood counts for at least 3 weeks) takes place in a medical facility. (1)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Low blood counts: neutropenia, low platelets, low red cell count (anemia), macrocytosis
Incidence: Very common/common per the Xromi product information — the expected, monitored mechanism of action, not an unexpected reaction
Nausea
Incidence: Common, per the clinician-authored database and the Xromi product information
Constipation
Incidence: Common, per the Xromi product information
Headache, dizziness
Incidence: Common, per the Xromi product information
Skin hyperpigmentation (skin, nails, or mouth), dry skin, hair loss
Incidence: Common, per the Xromi product information and the clinician-authored database
Reduced sperm count/production in men (very common, usually reversible)
Incidence: Very common, per the Xromi product information
Vomiting, diarrhea, fever, peripheral neuropathy
Incidence: Reported in the clinician-authored database; not independently confirmed by the external source reviewed in this pass, presented as DB-sourced pending further verification
Unusual bruising or bleeding
What to do: Contact a healthcare professional promptly if this develops. (2)
Persistent fever or chills
What to do: Contact a healthcare professional promptly if this develops. (2)
Mouth sores (stomatitis) or a skin rash
What to do: Contact a healthcare professional promptly if this develops. (2) (1)
Yellowing of the skin or eyes (jaundice), or other signs of liver problems
What to do: Contact a healthcare professional promptly if this develops. (2) (1)
A new skin sore or ulcer, especially on the legs
What to do: Contact a healthcare professional promptly if this develops. (1)
Shortness of breath or chest pain
What to do: Contact a healthcare professional promptly if this develops. (2)
Vision changes, light sensitivity, eye redness, or eye pain
What to do: Contact a healthcare professional promptly — this can be a sign of a rare eye condition (limbal stem cell deficiency). (1)
Serious warnings
Contraindications — serious
Symptoms: Contraindications: hypersensitivity to hydroxycarbamide or any ingredient; severe hepatic impairment (Child-Pugh class C); severe renal impairment (creatinine clearance under 30 mL/min); toxic-range bone marrow suppression; pregnancy; breastfeeding; and taking antiretroviral medicines for HIV at the same time. Tell your prescriber if any of these apply to you.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (1)
Seek immediate medical attention if you experience severe allergic reactions (such as swelling of the face, lips, or throat, or difficulty breathing), severe skin rash, signs of infection (high fever, severe sore throat), or symptoms of liver or kidney problems (such as dark urine, severe abdominal pain, or yellowing of the skin/eyes) — serious
Symptoms: Seek immediate medical attention if you experience severe allergic reactions (such as swelling of the face, lips, or throat, or difficulty breathing), severe skin rash, signs of infection (high fever, severe sore throat), or symptoms of liver or kidney problems (such as dark urine, severe abdominal pain, or yellowing of the skin/eyes).
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Bone marrow suppression — serious
Symptoms: Bone marrow suppression: a full blood count must be checked before starting and repeatedly during treatment. Low white blood cells (leukopenia) is the first and most common sign; low platelets and anemia occur less often. If low counts occur, your prescriber will withhold dosing and monitor weekly until recovery, then typically restart at a lower dose — this is a prescriber-managed process. Monitoring schedule: monthly blood counts for the first 2 months, every 4 weeks during dose adjustment, then every 2-3 months once on a stable maintenance dose.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (1)
Xromi's product information states it must not be used during pregnancy (reproductive toxicity has been shown) and must not be used while breastfeeding, since it passes into breast milk — serious
Symptoms: Xromi's product information states it must not be used during pregnancy (reproductive toxicity has been shown) and must not be used while breastfeeding, since it passes into breast milk. If you are pregnant, think you may be pregnant, or are breastfeeding, contact your prescriber promptly so the clinician can determine whether and how treatment should be adjusted or discontinued — do not decide this yourself.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Secondary cancer risk with long-term use — serious
Symptoms: Secondary cancer risk with long-term use: secondary leukaemia and skin cancer have been reported with long-term hydroxycarbamide therapy. Protect skin from sun exposure and self-check skin regularly during and after treatment.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (1)
Fertility and contraception — serious
Symptoms: Fertility and contraception: women of childbearing potential should use contraception before, during, and for 6 months after treatment. Men should use contraception for 3 months after stopping treatment and should discuss sperm cryopreservation with their doctor before starting, since reversible reduced sperm count/production is very common with hydroxycarbamide.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Rare eye condition (limbal stem cell deficiency) — serious
Symptoms: Rare eye condition (limbal stem cell deficiency): vision changes, light sensitivity, eye redness, or eye pain should be reported to your doctor promptly for assessment by an eye specialist. Your prescriber may temporarily pause or, if confirmed, permanently stop treatment.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Any change to your Xromi treatment, including stopping it, must be planned with your prescriber — unplanned stopping may increase the risk of sickle cell crises — serious
Symptoms: Any change to your Xromi treatment, including stopping it, must be planned with your prescriber — unplanned stopping may increase the risk of sickle cell crises. Contact your prescriber about any concern with continuing treatment.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Antiretroviral medicines for HIV | Xromi must not be combined with antiretroviral medicines, as this may cause treatment failure and toxicities, in some cases fatal. | (1) |
| Radiotherapy or chemotherapy (previous or concurrent) | Myelosuppressive (blood-count-lowering) effects may be increased. | (1) |
| Live vaccines | Increased risk of severe or fatal infection in immunosuppressed patients; live vaccines are not recommended while taking Xromi. | (1) |
| Interferon | Increased risk of skin vasculitis, including vasculitic ulceration and gangrene. | (1) |
| Continuous glucose monitoring (CGM) systems | Xromi may falsely elevate glucose readings on certain CGM systems, which could mask a real low-blood-sugar (hypoglycemic) episode. Tell your diabetes team you are taking Xromi if you use a CGM system. | (1) |
| Laboratory testing (not a medicine interaction) | Hydroxycarbamide can interfere with certain lab assays (urease, uricase, and lactic dehydrogenase), which can affect measured urea, uric acid, and lactic acid results. Tell any laboratory or clinician ordering these tests that you take Xromi. | (1) |
| Other medications that affect the liver, kidneys, or bone marrow | The clinician-authored database notes a general interaction risk with other medications affecting bone marrow, liver, or kidney function. Always inform your healthcare provider of all medicines and supplements you are taking. | (2) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Xromi must not be used during pregnancy — reproductive toxicity has been shown in studies. Women of childbearing potential should use contraception before, during, and for 6 months after treatment. If you are planning a pregnancy, discuss this with your prescriber as early as possible — pregnancy planning and any treatment interruption or change must be planned together with your prescriber, not decided on your own; the product information describes stopping treatment 3-6 months before conception where possible, but the exact timing and process is a decision for your prescriber to make with you. (1)
Breastfeeding
Hydroxycarbamide passes into human breast milk, and the product information states it must not be used while breastfeeding. If you are breastfeeding or planning to, contact your prescriber promptly — do not decide on your own whether to continue or stop; let your clinician advise on the safest plan for you and your baby. (1)
Children
Xromi is approved from 9 months of age for sickle cell disease. Dosing uses the same weight-based mg/kg schedule as adults (starting 15 mg/kg/day, titrated by the prescriber up to a maintenance range of 20-25 mg/kg/day, maximum 35 mg/kg/day) and is individually adjusted based on blood counts and response. (1)
Renal_impairment
Renal impairment: for creatinine clearance 60 mL/min or below, the starting dose is reduced by 50%; creatinine clearance below 30 mL/min is a contraindication (Xromi must not be given). Hepatic impairment: no specific numeric dose-adjustment data exist, but close monitoring of blood counts is advised, and dose reduction may be considered if clinically indicated; severe hepatic impairment (Child-Pugh class C) is a contraindication. (1)
Hepatic_impairment
Renal impairment: for creatinine clearance 60 mL/min or below, the starting dose is reduced by 50%; creatinine clearance below 30 mL/min is a contraindication (Xromi must not be given). Hepatic impairment: no specific numeric dose-adjustment data exist, but close monitoring of blood counts is advised, and dose reduction may be considered if clinically indicated; severe hepatic impairment (Child-Pugh class C) is a contraindication. (1)
Monitoring
(1)Storage
Store Xromi in a refrigerator (2-8°C). After first opening, discard any unused solution after 12 weeks. Keep the bottle tightly closed and out of reach of children. (This corrects an earlier room-temperature storage note in the clinician-authored database, which was not consistent with the official product information reviewed in this pass.)
Professional information
Clinician-facing context only. This section does not replace current product labeling.
UK/EU (Xromi oral solution)
Indication: Prevention of vaso-occlusive complications of sickle cell disease
Dose summary: Starting dose 15 mg/kg/day; increase by 5 mg/kg/day approximately every 8 weeks until mild myelosuppression is achieved (neutrophils 1,500-4,000/microliter, platelets maintained above 80,000/microliter); usual maintenance 20-25 mg/kg/day; maximum 35 mg/kg/day. Monitoring: monthly full blood count for the first 2 months, every 4 weeks during dose adjustment, then every 2-3 months at a stable maintenance dose. Clinical response may take 3-6 months; a 6-month trial at the maximum tolerated dose is generally needed before treatment is judged to have failed.
Renal context: Creatinine clearance ≤60 mL/min: reduce the initial dose by 50%. Creatinine clearance <30 mL/min: contraindicated. Close monitoring is advised across all degrees of renal impairment. Severe hepatic impairment (Child-Pugh C) is also contraindicated; no specific numeric hepatic dose-adjustment schedule was established in the source reviewed. (2) (1)
Frequently asked questions
What is Xromi used for?
Xromi's confirmed approved use is prevention of vaso-occlusive complications (including painful crises) of sickle cell disease in patients over 9 months of age. The clinician-authored database also describes a reduced need for blood transfusions; this specific transfusion-reduction claim was not independently confirmed by the external source reviewed in this pass and is presented as DB-sourced pending further verification.
How does Xromi work?
Xromi increases the production of fetal hemoglobin, which helps prevent red blood cells from sickling and blocking blood vessels.
Can children take Xromi?
Yes, Xromi is approved for use in children with sickle cell disease from 9 months of age. Dosing is weight-based and individually adjusted by the prescriber according to response and blood counts.
What should I do if I miss a dose?
The product information for Xromi does not give specific missed-dose guidance. Contact your prescriber or pharmacist for advice on your next dose rather than deciding on your own whether to take, skip, or double it.
Are there foods or medicines I should avoid while taking Xromi?
Live vaccines are not recommended while taking Xromi because of increased infection risk. Xromi must not be combined with antiretroviral medicines for HIV. Discuss all medicines and supplements you take with your doctor to check for other interactions.
What are the serious side effects of Xromi?
Serious side effects include severe infections, unusual bleeding, liver or kidney problems, and allergic reactions. Seek medical help if these occur.
How often do I need blood tests while on Xromi?
Regular blood tests are needed, especially at the start of treatment, to monitor blood counts and organ function.
What is the mechanism of action of Hydroxycarbamide (hydroxyurea)?
Mechanism-of-action detail beyond the recorded indications and dosing above was not captured as a separate field in the clinician-authored database record for this medicine; see how_to_take and professional_information.regional_dosing for the recorded clinical detail. (2)
What is the generic name of Hydroxycarbamide (Hydroxyurea)?
The generic name is Hydroxycarbamide (hydroxyurea). It is sold under brand names including Hydrea, Xromi, Cytodrox, Droxia, Hydrostat, Myelostat.
What class of drug is Hydroxycarbamide (hydroxyurea)?
Hydroxycarbamide (Hydroxyurea) is classed as: Ribonucleotide reductase inhibitor; disease-modifying agent for sickle cell disease (this specific Xromi oral-solution product). The same molecule, hydroxycarbamide/hydroxyurea, is also used as an antineoplastic (cancer) agent in other capsule/tablet products under different brand names — see brand_names_note..
References
- Xromi 100 mg/ml oral solution — Summary of Product Characteristicselectronic Medicines Compendium (UK) · United Kingdom · accessed 2026-08-06 · source 1
- Xromi content model from internal databaseMedGuideGlobal clinical database · not region-specific · accessed 2026-08-06 · source 2
- Hydroxyurea — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 3
- Hydroxycarbamide — RxNorm normalized drug concept (RXCUI 5552)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 4
Brand names by country
Single-ingredient Hydroxycarbamide (hydroxyurea) names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
India
- Cytodrox500 mg · Cipla Limited
- Myelostat500 mg · Zydus Lifesciences Limited
- Hydreo500 mg · Knoll Healthcare Pvt Ltd
- Hydrosar500 mg · Sarabhai Chemicals Pvt Ltd
- Riborea500 mg · MG Nutraceuticals