Sickle Cell Anemia
In patients treated for sickle cell anemia in the Multicenter Study of Hydroxyurea in Sickle Cell Anemia,1 the most common adverse reactions were hematologic, with neutropenia, and low reticulocyte and platelet levels necessitating temporary cessation in almost all patients. Hematologic recovery usually occurred in two weeks.
Non-hematologic events that possibly were associated with treatment include hair loss, skin rash, fever, gastrointestinal disturbances, weight gain, bleeding, and parvovirus B-19 infection; however, these non-hematologic events occurred with similar frequencies in the hydroxyurea and placebo treatment groups. Melanonychia has also been reported in patients receiving DROXIA for SCA.
Adverse events associated with the use of hydroxyurea in the treatment of neoplastic diseases, in addition to hematologic effects include: gastrointestinal symptoms (stomatitis, anorexia, nausea, vomiting, diarrhea, and constipation), and dermatological reactions such as maculopapular rash, skin ulceration, dermatomyositis-like skin changes, peripheral erythema, and facial erythema. Hyperpigmentation, atrophy of skin and nails, scaling, and violet papules have been observed in some patients after several years of long-term daily maintenance therapy with hydroxyurea. Skin cancer has been reported. Cutaneous vasculitic toxicities, including vasculitic ulcerations and gangrene, have occurred in patients with myeloproliferative disorders during therapy with hydroxyurea. These vasculitic toxicities were reported most often in patients with a history of, or currently receiving, interferon therapy (see WARNINGS). Dysuria and alopecia have been reported. Large doses may produce drowsiness. Neurological disturbances have occurred and were limited to headache, dizziness, disorientation, hallucinations, and convulsions. Hydroxyurea may cause temporary impairment of renal tubular function accompanied by elevations in serum uric acid, blood urea nitrogen (BUN), and creatinine levels. Abnormal bromsulphalein (BSP) retention has been reported. Fever, chills, malaise, edema, asthenia, and elevation of hepatic enzymes have also been reported.
The association of hydroxyurea with the development of acute pulmonary reactions consisting of diffuse pulmonary infiltrates, fever, and dyspnea has been reported. Pulmonary fibrosis also has been reported.
In HIV-infected patients who received hydroxyurea in combination with antiretroviral agents, in particular, didanosine plus stavudine, fatal and nonfatal pancreatitis and hepatotoxicity, and severe peripheral neuropathy have been reported. Patients treated with hydroxyurea in combination with didanosine, stavudine, and indinavir in Study ACTG 5025 showed a median decline in CD4 cells of approximately 100/mm³. (See WARNINGS and PRECAUTIONS.)