Hydroxyurea

Hydroxyurea is most often prescribed for patients with chronic myeloid leukemiacervical Cancer and a variety of other malignant tumors and myeloproliferative disorders. It is also used in sickle cell disease and in HIV infection.

Mechanism of action

Hydroxyurea becomes a free radicals nitroxide In psoriasis, it is believed to work by reducing the replication of DNA within basal cell of the epidermis. A response is seen in approximately half of treated patients, sometimes those resistant to other therapies such as methotrexate, acitretin, or phototherapy. Improvement usually begins about two weeks after starting treatment, and is greatest after about eight weeks.

In resistant cases, hydroxyurea can be combined with caution with other antipsoriatic drugs. Caution should be taken when combining with methotrexate as both drugs can suppress the increased function of the bone marrow. toxicity.

Hydroxyurea should not be taken during pregnancy as it is likely to cause fetal abnormalities. It should not be taken by a breastfeeding mother. Its safety in children is unknown.

Side effects

• Bone marrow toxicity is monitored by regular blood counts ('CBC' or 'FBC'). If toxicity occurs, the dose is generally reduced. Up to a third of patients develop some toxicity, which can occur at any time during a treatment cycle:
  • Leukopenia (reduced white blood cell count)
  • Anemia (reduced red blood cell count)
  • Thrombocytopenia (reduced platelet tell)
  • Pancytopenia (reduction in all types of blood cells)
  • Macrocytosis (red blood cells larger than normal) occurs in all patients as the red blood cells carry more hemoglobin and they become rounder, and the bone marrow produces "megaloblasts." This is not a problem and recovers when the drug is stopped.
• Liver toxicity is rare, and hydroxyurea can be used safely in patients with liver problems caused by methotrexate. However, slight hepatitis has been occasionally reported.
• Renal toxicity does not appear to be a problem in psoriasis, but it has been reported in leukemia patients treated with hydroxyurea.
• A generalized yellowish gray skin pigmentation and widespread hair Weight loss can occur, but are rare.
• Painful leg ulcers Similar to pyoderma gangrenous and a type of dermatomyositis eruption have been reported in patients with leukemia.
• Drug-related lupus is rare and can cause photosensitivity with muscle or joint pain.
• An increased risk of skin cancer has been reported.
• The risk of other malignancies due to hydroxyurea that arises in patients with psoriasis is unknown, but is believed to be extremely low.
• Hydroxyurea interferes with DNA synthesis and therefore may not be safe during pregnancy. Conception should be avoided in male and female patients treated with hydroxyurea, although no problems have been reported.
• An overdose can be fatal; the blood count should be carefully monitored and a blood transfusion given if necessary. Fingers, toes, and mouth may become red, swollen, and painful.