Hydroxycarbamide is a cytostatic drug. It is used in the treatment of malignant blood diseases such as leukemia. It is also used in HIV infections as part of antiretroviral treatment.
What is hydroxycarbamide?
Hydroxycarbamide is one of the drugs with cytostatic activity. It is used primarily in chronic myeloid leukemia (CML). It is also occasionally used in the treatment of sickle cell anemia (formation of abnormal hemoglobin) and in HIV infection for antiretroviral treatment. Commercially, hydroxycarbamide is available in the form of capsules. It is a hydroxylated urea, which exists as a white and crystalline hydroscopic powder and is soluble in water. Hydroxycarbamide is also known as hydroxyurea or hydroxyurea.
Pharmacological effects on the body and organs
The exact mode of action of hydroxycarbamide is not yet fully understood. As a cytostatic agent, the active ingredient itself inhibits cell growth and division as well as proliferation. It interferes with DNA synthesis. Hydroxycarbamide is said to interfere with the synthesis of individual nucleotides. The active ingredient appears to block the enzyme responsible for converting ribose into deoxyribose. In addition, hydroxycarbamide could contribute to a disruption of the incorporation of thymine nucleotides into the DNA chain. The effect in the treatment of sickle cell anemia is also not yet clear. Here, there is probably an increase in the concentration of hemoglobin as in an unborn child. This impedes the fiber formation of the abnormal hemoglobin and thus the curvature of the red blood cells. There is no clumping because the blood remains more fluid overall.
Medical use and use for treatment and prevention.
Hydroxycarbamide is used in the treatment of chronic myeloid leukemia (CML for short, characterized by severe proliferation of white blood cells and granulocytes), essential thrombocythemia (severe proliferation of platelets in the blood), polycythaemia vera (proliferation of all three blood cell series in the blood), sickle cell anemia, and thalassemia major (insufficient production of normal HbA1). Rarely, it is also used in antiretroviral therapy for HIV infection. Hydroxycarbamide must always be taken according to the physician’s instructions. In the treatment of CML, the initial dose for adults is 40 mg/kg body weight per day. The dose is then adjusted individually depending on the white blood cell count. For the treatment of polycythaemia vera, the initial daily dose is 15 to 20 mg/kg body weight. Again, individual adjustment is made, always depending on the blood cell count. The dose for essential thrombocythemia is 15 mg/kg body weight daily and is individually adjusted depending on the blood cell count. The effect in elderly patients may be stronger, so the dosage is usually lower. Use of hydroxycarbamide is not indicated in cases of hypersensitivity to the active substance, severe bone marrow hematopoiesis disorders, platelet and white blood cell deficiency, and anemia. In the case of previous therapy of the same type, liver or kidney dysfunction, and concomitant treatment with cytostatic drugs from the antimetabolite subgroup, the physician must carefully weigh the benefits and risks of using hydroxycarbamide. Hydroxycarbamide must also not be used during pregnancy and lactation. Treatment of children is possible with the drug, but it is rare because most of these conditions do not occur in children.
Risks and side effects
Hydroxycarbamide may cause different side effects. They may be very rare to common, but they do not have to be. Common side effects include disturbances in bone marrow formation, white blood cell deficiency, megaloblast formation, and constipation or diarrhea. Occasionally, nausea and vomiting, malaise, chills, anemia, a lack of platelets, redness of the skin on the legs and arms, facial flushing, or blotchy-blistery rash may occur while taking hydroxycarbamide.Increases in blood urea levels, liver enzyme levels, blood bilirubin levels, blood uric acid levels, and blood creatinine levels are also not uncommon. In rare cases, headache, hair loss, dizziness, fever, shortness of breath, confusion, delusions, urinary retention, water retention in the lungs, and allergic alveolitis occur. Very rare side effects include impaired kidney function. If hydroxycarbamide is taken in combination with antiviral agents, liver damage or inflammation of the pancreas may occur. If concomitant or preceded by concomitant cytostatic therapy or radiation therapy, certain side effects (e.g., bone marrow dysfunction, gastrointestinal symptoms, skin flushing) may be exacerbated.
