Massive accidental overdose of hydroxyurea in a young child with sickle cell anemia.
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SUBMITTER: Miller ST
PROVIDER: S-EPMC3193862 | biostudies-literature | 2012 Jul
REPOSITORIES: biostudies-literature
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Massive accidental overdose of hydroxyurea in a young child with sickle cell anemia.
Miller Scott T ST Rey Kathy K He Jin J Flanagan Jonathan J Fish Billie J BJ Rogers Zora R ZR Wang Winfred C WC Ware Russell E RE
Pediatric blood & cancer 20110708 1
The Pediatric Hydroxyurea Phase III Clinical Trial (BABY HUG) confirmed safety and efficacy of hydroxyurea therapy for infants with sickle cell anemia. Treatment was associated with reduction in rates of pain, acute chest syndrome, hospitalizations, and blood transfusions; improved hematologic values; and, perhaps, preservation of organ function. During the study, a 2-year-old ingested at one time an entire 35-day supply of hydroxyurea (612 mg/kg body weight). Despite a serum level of 7,756 µM 4 ...[more]
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Project description:Sickle cell anemia (SCA) is a severe, inherited hemoglobin disorder affecting 100,000 persons in the US and millions worldwide. Hydroxyurea, a once daily oral medication, has emerged as the primary disease-modifying therapy for SCA. The accumulated body of evidence over 30 years demonstrates that hydroxyurea is a safe and effective therapy for SCA, but hydroxyurea remains underutilized for a variety of reasons.In this review, we summarize the available evidence regarding the pharmacology, clinical, and laboratory benefits, and safety of hydroxyurea therapy for the treatment of SCA. The purpose of this review is to provide the reader a comprehensive understanding of hydroxyurea and to reinforce the fact that hydroxyurea is a safe and effective medication for the treatment of SCA.In our opinion, hydroxyurea therapy should be considered standard-of-care for SCA, representing an essential component of patient management. Early initiation and broader use of hydroxyurea will alter the natural history of SCA, so affected children can live longer and healthier lives. In addition, hydroxyurea use should be extended to low-resource settings such as sub-Saharan Africa, where the burden of SCA and the need for hydroxyurea is arguably the greatest.
| S-EPMC5868345 | biostudies-literature
Project description:Hydroxyurea has many characteristics of an ideal drug for sickle cell anemia (SCA) and provides therapeutic benefit through multiple mechanisms of action. Over the past 25 years, substantial experience has accumulated regarding its safety and efficacy for patients with SCA. Early proof-of-principle studies were followed by prospective phase 1/2 trials demonstrating efficacy in affected adults, then adolescents and children, and more recently infants and toddlers. The phase 3 National Heart, Lung and Blood Institute-sponsored Multicenter Study of Hydroxyurea trial proved clinical efficacy for preventing acute vaso-occlusive events in severely affected adults. Based on this cumulative experience, hydroxyurea has emerged as an important therapeutic option for children and adolescents with recurrent vaso-occlusive events; recent evidence documents sustained long-term benefits with prevention or reversal of chronic organ damage. Despite abundant evidence for its efficacy, however, hydroxyurea has not yet translated into effective therapy for SCA. Because many healthcare providers have inadequate knowledge about hydroxyurea, patients and families are not offered treatment or decline because of unrealistic fears. Limited support for hydroxyurea by lay organizations and inconsistent medical delivery systems also contribute to underuse. Although questions remain regarding its long-term risks and benefits, current evidence suggests that many young patients with SCA should receive hydroxyurea treatment.
| S-EPMC2902131 | biostudies-literature
Project description:Background and objectiveSusceptibility to encapsulated bacteria is well known in sickle cell disease (SCD). Hydroxyurea use is common in adults and children with SCD, but little is known about hydroxyurea's effects on immune function in SCD. Because hydroxyurea inhibits ribonucleotide reductase, causing cell cycle arrest at the G1-S interface, we postulated that hydroxyurea might delay transition from naive to memory T cells, with inhibition of immunologic maturation and vaccine responses.MethodsT-cell subsets, naive and memory T cells, and antibody responses to pneumococcal and measles, mumps, and rubella vaccines were measured among participants in a multicenter, randomized, double-blind, placebo-controlled trial of hydroxyurea in infants and young children with SCD (BABY HUG).ResultsCompared with placebo, hydroxyurea treatment resulted in significantly lower total lymphocyte, CD4, and memory T-cell counts; however, these numbers were still within the range of historical healthy controls. Antibody responses to pneumococcal vaccination were not affected, but a delay in achieving protective measles antibody levels occurred in the hydroxyurea group. Antibody levels to measles, mumps, and rubella showed no differences between groups at exit, indicating that effective immunization can be achieved despite hydroxyurea use.ConclusionsHydroxyurea does not appear to have significant deleterious effects on the immune function of infants and children with SCD. Additional assessments of lymphocyte parameters of hydroxyurea-treated children may be warranted. No changes in current immunization schedules are recommended; however, for endemic disease or epidemics, adherence to accelerated immunization schedules for the measles, mumps, and rubella vaccine should be reinforced.
| S-EPMC4179098 | biostudies-literature
Project description:In the BABY HUG trial, young children with sickle cell anemia randomized to receive hydroxyurea had fewer episodes of pain, hospitalization, and transfusions. With anticipated broader use of hydroxyurea in this population, we sought to estimate medical costs of care in treated versus untreated children.The BABY HUG database was used to compare inpatient events in subjects receiving hydroxyurea with those receiving placebo. Unit costs were estimated from the 2009 MarketScan Multi-state Medicaid Database for children with sickle cell disease, aged 1 to 3 years. Inpatient costs were based on length of hospital stay, modified by the occurrence of acute chest syndrome, splenic sequestration, or transfusion. Outpatient expenses were based on the schedule required for BABY HUG and a "standard" schedule for 1- to 3-year-olds with sickle cell anemia.There were 232 hospitalizations in the subjects receiving hydroxyurea and 324 in those on placebo; length of hospital stay was similar in the 2 groups. Estimated outpatient expenses were greater in those receiving hydroxyurea, but these were overshadowed by inpatient costs. The total estimated annual cost for those on hydroxyurea ($11?072) was 21% less than the cost of those on placebo ($13?962; P = .038).Savings on inpatient care resulted in a significantly lower overall estimated medical care cost for young children with sickle cell anemia who were receiving hydroxyurea compared with those receiving placebo. Because cost savings are likely to increase with age, these data provide additional support for broad use of hydroxyurea treatment in this population.
| S-EPMC4074648 | biostudies-literature
Project description:The Multicenter Study of Hydroxyurea (HU) in Sickle Cell Anemia (MSH) previously showed that daily oral HU reduces painful sickle cell (SS) crises by 50% in patients with moderate to severe disease. The morbidity associated with this disease is known to have serious negative impact on the overall quality of life(QOL) of affected individuals.The data in this report were collected from the 299 patients enrolled in the MSH. Health quality of llife (HQOL) measures were assessed in the MSH as a secondary endpoint to determine if the clinical benefit of HU could translate into a measurable benefit perceptible to the patients. HQOL was assessed with the Profile of Mood States, the Health Status Short Form 36 (SF-36), including 4-week pain recall, and the Ladder of Life, self-administered twice 2-weeks apart pre-treatment and every 6 months during the two-year, randomized, double-blind, treatment phase. The effects of factors including randomized treatment, age, gender, pre-treatment crises frequency, Hb-F level mean, daily pain from 4-week pre-treatment diaries, and 2-year Hb-F response level (low or high) were investigated.Over two years of treatment, the benefit of HU treatment on QOL, other than pain scales, was limited to those patients taking HU who maintained a high HbF response, compared to those with low HbF response or on placebo. These restricted benefits occurred in social function, pain recall and general health perception. Stratification according to average daily pain prior to treatment showed that responders to HU whose average daily pain score was 5-9 (substantial pain) achieved significant reduction in the tension scale compared to the placebo group and to non-responders. HU had no apparent effect on other QOL measures.Treatment of SS with HU improves some aspects of QOL in adult patients who already suffer from moderate-to-severe SS.
| S-EPMC1569824 | biostudies-other
Project description:Background: Despite a high incidence of sickle cell anemia, hydroxyurea (HU) treatment is rarely used in the DR Congo. This study aims to assess the efficacy of HU, the incidence of side effects that may limit its use in adults and to determine the dose needed for clinical improvement in patients. Methods: In a prospective study, patients received an initial dose of 15 mg/kg/day which was increased by 5 mg/kg every 6 months, up to a maximum of 30 mg/kg/day. The response and side effects to HU were evaluated biologically and clinically every 3 months during a 2-year period. Results: Seventy adult patients with a moderate or severe clinical phenotype initiated treatment. Only minor side effects were reported. At the end of the 2-year treatment phase, 45 (64.3%) had dropped out, of whom 33 were without a clear reason. Clinical and biological improvement was more marked during the first year. There was a reduction in severe vaso-occlusive crises (p < 0.001), need for transfusion (p < 0.001), and hospitalization days (p = 0.038). Fetal hemoglobin (HbF) levels increased on average 2.9 times after 12 months (p < 0.001). The increase in mean corpuscular volume was greater in the first year (p < 0.001) than in the second year (p = 0.041). The decrease in leukocytes (p < 0.001) was significant during the first year. In 70% of patients, the 20 mg/kg/day dose was needed to reach the 20% HbF threshold. Conclusion: HU is effective and well tolerated. The magnitude of the response varies from one patient to another. Improvement of clinical manifestations is achieved in most patients with a relatively low dose. Effective implementation of HU treatment will require improved adherence to treatment.
| S-EPMC10435708 | biostudies-literature
Project description:BackgroundHydroxyurea improves laboratory parameters and prevents acute clinical complications of sickle cell anemia (SCA) in children and adults, but its effects on organ function remain incompletely defined.MethodsTo assess the safety and efficacy of hydroxyurea in young children with SCA and to prospectively assess kidney and brain function, 14 young children (mean age 35 months) received hydroxyurea at a mean maximum tolerated dose (MTD) of 28 mg/kg/day.ResultsAfter a mean of 25 months, expected laboratory effects included significant increases in hemoglobin, MCV and %HbF along with significant decreases in reticulocytes, absolute neutrophil count, and bilirubin. There was no significant increase in glomerular filtration rate by DTPA clearance or Schwartz estimate. Mean transcranial Doppler (TCD) velocity changes were -25.6 cm/sec (P < 0.01) and -26.8 cm/sec (P < 0.05) in the right and left MCA vessels, respectively. At study exit, no child had conditional or abnormal TCD values, and none developed brain ischemic lesions or vasculopathy progression by MRI/MRA. Growth and neurocognitive scores were preserved and Impact-on-Family scores improved.ConclusionsThese pilot data indicate hydroxyurea at MTD is well-tolerated by both children and families, and may prevent chronic organ damage in young children with SCA.
| S-EPMC5600482 | biostudies-literature
Project description:BACKGROUND:Hydroxyurea is an effective treatment for sickle cell anemia, but few studies have been conducted in sub-Saharan Africa, where the burden is greatest. Coexisting conditions such as malnutrition and malaria may affect the feasibility, safety, and benefits of hydroxyurea in low-resource settings. METHODS:We enrolled children 1 to 10 years of age with sickle cell anemia in four sub-Saharan countries. Children received hydroxyurea at a dose of 15 to 20 mg per kilogram of body weight per day for 6 months, followed by dose escalation. The end points assessed feasibility (enrollment, retention, and adherence), safety (dose levels, toxic effects, and malaria), and benefits (laboratory variables, sickle cell-related events, transfusions, and survival). RESULTS:A total of 635 children were fully enrolled; 606 children completed screening and began receiving hydroxyurea at a mean (±SD) dose of 17.5±1.8 mg per kilogram per day. The retention rate was 94.2% at 3 years of treatment. Hydroxyurea therapy led to significant increases in both the hemoglobin and fetal hemoglobin levels. Dose-limiting toxic events regarding laboratory variables occurred in 5.1% of the participants, which was below the protocol-specified threshold for safety. During the treatment phase, 20.6 dose-limiting toxic effects per 100 patient-years occurred, as compared with 20.7 events per 100 patient-years before treatment. As compared with the pretreatment period, the rates of clinical adverse events decreased with hydroxyurea use, including rates of vaso-occlusive pain (98.3 vs. 44.6 events per 100 patient-years; incidence rate ratio, 0.45; 95% confidence interval [CI], 0.37 to 0.56), nonmalaria infection (142.5 vs. 90.0 events per 100 patient-years; incidence rate ratio, 0.62; 95% CI, 0.53 to 0.72), malaria (46.9 vs. 22.9 events per 100 patient-years; incidence rate ratio, 0.49; 95% CI, 0.37 to 0.66), transfusion (43.3 vs. 14.2 events per 100 patient-years; incidence rate ratio, 0.33; 95% CI, 0.23 to 0.47), and death (3.6 vs. 1.1 deaths per 100 patient-years; incidence rate ratio, 0.30; 95% CI, 0.10 to 0.88). CONCLUSIONS:Hydroxyurea treatment was feasible and safe in children with sickle cell anemia living in sub-Saharan Africa. Hydroxyurea use reduced the incidence of vaso-occlusive events, infections, malaria, transfusions, and death, which supports the need for wider access to treatment. (Funded by the National Heart, Lung, and Blood Institute and others; REACH ClinicalTrials.gov number, NCT01966731 .).
| S-EPMC6454575 | biostudies-literature
Project description: Not available
| S-EPMC5389903 | biostudies-literature
Project description:Hydroxyurea is FDA-approved and now increasingly used for children with sickle cell anemia (SCA), but dosing strategies, pharmacokinetic (PK) profiles, and treatment responses for individual patients are highly variable. Typical weight-based dosing with step-wise escalation to maximum tolerated dose (MTD) leads to predictable laboratory and clinical benefits, but often takes 6 to 12 months to achieve. The Therapeutic Response Evaluation and Adherence Trial (TREAT, NCT02286154) was a single-center study designed to prospectively validate a novel personalized PK-guided hydroxyurea dosing strategy with a primary endpoint of time to MTD. Enrolled participants received a single oral 20 mg/kg dose of hydroxyurea, followed by a sparse PK sampling approach with three samples collected over three hours. Analysis of individual PK data into a population PK model generated a starting dose that targets the MTD. The TREAT cohort (n = 50) was young, starting hydroxyurea at a median age of 11 months (IQR 9-26 months), and PK-guided starting doses were high (27.7 ± 4.9 mg/kg/d). Time to MTD was 4.8 months (IQR 3.3-9.3), significantly shorter than comparison studies (p < 0.0001), thus meeting the primary endpoint. More remarkably, the laboratory response for participants starting with a PK-guided dose was quite robust, achieving higher hemoglobin (10.1 ± 1.3 g/dL) and HbF (33.3 ± 9.1%) levels than traditional dosing. Though higher than traditional dosing, PK-guided doses were safe without excess hematologic toxicities. Our data suggest early initiation of hydroxyurea, using a personalized dosing strategy for children with SCA, provides laboratory and clinical response beyond what has been seen historically, with traditional weight-based dosing.
| S-EPMC6639795 | biostudies-literature