Treatment with the drug Hydroxycarbamide-native should be conducted under the supervision of a doctor who has experience in the use of antitumor therapy.
Before each course and periodically during treatment, it is necessary to monitor the functions of the bone marrow, liver and kidneys. Determination of hemoglobin, leukocytes and platelets should be conducted at least once a week during the entire period of treatment with the drug. Treatment is prescribed only if the white blood cell count exceeds 2500 / μL, and the platelet count is 100,000 / μL. If, during treatment, it is found that the white blood cell count is less than 2500 / μL or platelets - less than 100,000 / μL, treatment should be suspended until their content is restored to normal.Severe form of anemia should be compensated before starting treatment with the drug.
During treatment with the drug, myelosuppression may develop, mainly leukopenia. Thrombocytopenia and anemia develop less frequently and very rarely without previous leukopenia. Myelosuppression is most likely in patients after recent previous radiation therapy or chemotherapy with other drugs. After recent radiation or chemotherapy, the drug should be used with caution because of the possible exacerbation of the post-radiation erythema and increased severity of side effects (bone marrow aplasia, dyspepsia and ulceration of the gastrointestinal tract).
If serious side effects occur on the part of the digestive organs (such as nausea, vomiting, anorexia), they usually stop the drug. With pain and discomfort in the development of mucositis in the area of radiation, local anesthetics and analgesics for oral administration are usually prescribed. In severe cases, drug therapy is temporarily suspended, and in very severe cases, temporary concomitant radiation therapy is canceled.
In the early stages of drug treatment, a moderate megaloblastic erythropoiesis is often observed. Morphological changes resemble pernicious anemia, however, they are not associated with a deficiency of vitamin B12 or folic acid. Due to the fact that macrocytosis can mask the deficiency of folic acid, regular determination of folic acid in serum is recommended.
Hydroxycarbamide can also slow the clearance of plasma iron and reduce the rate of iron utilization by red blood cells, however, this does not affect the lifetime of red blood cells.
Cases of pancreatitis and hepatotoxicity (with possible fatal outcome) were noted in HIV-infected patients who were taking hydroxycarbamide together with antiretroviral drugs, in particular with didanosine (in combination with stavudine or without it). In connection with this, joint use of these drugs should be avoided. Also, cases of development of peripheral neuropathy, sometimes severe, were noted in HIV-infected patients who were taking hydroxycarbamide, together with antiretroviral drugs, including didanosine (in combination with stavudine or without it).
During treatment, patients should consume a sufficient amount of fluid. It may be necessary to reduce the dose of the drug for violations of kidney function. The drug should be used with caution in patients with impaired renal and hepatic function.
During treatment with the drug, skin toxic toxic vasculitis was observed in patients with myeloproliferative diseases, including vasculitic ulceration and gangrene. The most frequently reported toxic vasculitis in patients who received or received interferon in the past. With the progression of vasculitic ulceration, the drug should be discontinued.
With prolonged use of the drug in patients with myeloproliferative diseases, such as true polycythemia and thrombocytopenia, cases of secondary leukemia are noted. It is not known what causes secondary leukemia: the use of hydroxycarbamide or the underlying disease.
With prolonged use of hydroxycarbamide, skin cancer has also been observed. Patients should be warned about the need to protect the skin from sunlight and carry out self-monitoring of skin condition.During planned visits to the doctor, the skin condition of the patient should be monitored in order to identify possible malignant changes.
Azospermia or oligospermia, sometimes reversible, have been observed in male patients. In this regard, patients should be informed about the possibility of preserving sperm before starting therapy.
In connection with the possible genotoxicity of the hydroxycarbamide, male patients taking the drug should be informed of the need for reliable contraception during treatment and at least one year after the end of therapy.
When vaccinated with live viral vaccines concurrently with hydroxyurea therapy, activation of vaccine virus replication and / or an increase in the development of adverse reactions due to the suppression of the protective mechanisms of the body caused by the use of hydroxycarbamide are possible. Vaccination with live vaccines during the application of hydroxycarbamide may lead to the development of severe infections. It is also possible to reduce the immune response to the administration of vaccines.
It should avoid the introduction of live vaccines during the period of drug therapy and consult a specialist.
Hydroxycarbamide possesses a cytotoxic effect, therefore it is necessary to observe caution when opening the capsules and avoid getting powder from the capsules on the skin, mucous membranes or inhaling the drug. If the contents of the capsule accidentally scattered, you should immediately collect the powder with a tissue in a plastic bag, tie it and discard it.
Application in pediatrics. Safety and effectiveness of the use of hydroxycarbamide in children is not established.
Since elderly patients are more likely to develop side effects when using hydroxycarbamide than younger patients, it may be necessary to use the drug in a reduced dose.