Hydroxyurea Medac (Hydroxycarbamide)

• Hydroxyurea Medac is used in hematologic disorders where abnormal cell proliferation is a key feature.
• Sickle cell disease: reduces frequency of painful crises and transfusion requirements.
• Chronic myelogenous leukemia: helps control leukemic cell growth.
• Polycythemia vera: lowers elevated red blood cell mass.
• Essential thrombocythemia: decreases platelet counts and thrombotic risk.
• Myeloproliferative disorders: improves overall disease management.

• Hydroxycarbamide inhibits the enzyme ribonucleotide reductase, the key catalyst for conversion of ribonucleotides to deoxyribonucleotides. By limiting deoxyribonucleotide pools, DNA synthesis is slowed, particularly in rapidly dividing hematopoietic cells. This cytostatic effect reduces abnormal proliferation of sickled erythrocytes, leukemic blasts, and megakaryocytes, thereby moderating disease activity. The drug’s action is dose‑dependent and reversible, allowing normal marrow recovery when treatment is paused.

Hydroxyurea can cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Fatigue: general tiredness and reduced energy.
• Low white blood cell count: mild neutropenia detectable on routine labs.

Serious or Rare Side Effects

• Severe bone marrow suppression: pancytopenia requiring medical intervention.
• Aplastic anemia: rare but potentially life‑threatening.
• Liver toxicity: elevated transaminases or hepatitis.

Before initiating therapy, clinicians should assess baseline laboratory values and monitor patients regularly.

• Monitor blood counts: perform regular CBC to detect myelosuppression.
• Assess renal and hepatic function: obtain baseline and periodic labs.
• Avoid use in patients with known hypersensitivity to hydroxyurea.
• Use caution with concomitant myelosuppressive therapies.
• Pregnancy and lactation: contraindicated unless benefits outweigh risks; discuss with physician.
• Store at ambient temperature below 25°C: keep in original container, protect from moisture and light.

Hydroxyurea may interact with several medicines, requiring careful evaluation.

Major Interactions (Avoid)

• Concurrent use with other myelosuppressive agents (e.g., azathioprine, cyclophosphamide) may cause profound bone‑marrow depression.
• Combination with antiretroviral drugs such as didanosine can increase toxicity.
• Co‑administration with live vaccines may reduce vaccine efficacy.

Moderate Interactions (Monitor Closely)

• Allopurinol: may increase hydroxyurea plasma levels; monitor for toxicity.
• NSAIDs: may exacerbate renal effects; check renal function.
• Phenytoin: may reduce hydroxyurea effectiveness; adjust dose if needed.