Hydroxyurea
HYDREA
Pronunciation: hye-drox-ee-yoor-EE-a
What it isRibonucleotide reductase inhibitor that raises fetal hemoglobin; sickle cell disease and myeloproliferative disease.
Why this oneReduces crises, acute chest syndrome and mortality in sickle cell disease, which supportive care alone does not.
What limits itMyelosuppression requires regular counts. Teratogenic, and it takes months for the fetal hemoglobin rise to show benefit.
Hydroxyurea prescription history
Animated chart of estimated U.S. prescriptions per year, Oral anticancer meds (1953–2026). Hydroxyurea enters in 1967 (estimated).
FDA-approved for
- sickle cell disease (1998)
- chronic myeloid leukemia, melanoma
Off-label
- thrombocythemia and polycythemia vera
Classes and tags
Clinical profile
Legacy pregnancy categoryD
Defining liabilityMyelosuppression and agent-specific hepatic, cardiac, pulmonary, neurologic or reproductive toxicity require oncology monitoring.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Neoplastic diseases | Adults | 15 mg/kg QD | Individualized to response/tumor type |
Renal Reduce dose 50% (7.5 mg/kg QD) if CrCl <60 mL/min or ESRD; on dialysis days give after hemodialysis
Hepatic Undefined — no data for adjustment; monitor hematologic parameters closely
Instructions
- Swallow capsules whole; do not open, break, or chew (cytotoxic drug)
- Base dose on actual or ideal body weight, whichever is less
- Prophylactic folic acid recommended
- Monitor blood counts at least weekly; correct severe anemia before starting
Available strengths
- cap 200, 300, 400, 500 mg
- tab 100, 1000 mg
- sol 100 mg/mL
Cautions
- Severe myelosuppression — do not initiate if bone marrow markedly depressed
- Hemolytic anemia
- Human carcinogen; secondary leukemia and skin cancer with long-term use
- Embryo-fetal toxicity
- Cutaneous vasculitic toxicities (ulcers, gangrene)
- Avoid live vaccines
- Pancreatitis, hepatotoxicity, neuropathy with concomitant antiretrovirals
- Radiation recall
- Macrocytosis (may mask pernicious anemia)
- Pulmonary toxicity/interstitial lung disease (incl. fatal)
Adverse reactions
- Hematologic (myelosuppression, leukopenia, thrombocytopenia, anemia)
- GI symptoms (nausea, vomiting, diarrhea, stomatitis)
- Anorexia
Pregnancy Can cause fetal harm (teratogenic/embryotoxic in animals); avoid pregnancy, use effective contraception
Lactation Excreted in human milk; discontinue breastfeeding during treatment
Cost
| Strength | #/mo | generic $/mo | brand $/mo | CostPlus | |
|---|---|---|---|---|---|
| 200 mg | cap | 30 qd | — | $21.87 | not offered |
| 300 mg | cap | 30 qd | — | $21.85 | not offered |
| 400 mg | cap | 30 qd | — | $23.45 | not offered |
| 500 mg | cap | 30 qd | $5.51 | — | offered |
Generic entry1995
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Self-check
- Which hemoglobin fraction does hydroxyurea raise?
Fetal hemoglobin. - How soon does that hemoglobin rise produce benefit?
Over months.