ABSTRACT
OBJECTIVE: In response to previously published findings of methylphenidate-induced chromosomal changes in children, this study was designed to determine whether methylphenidate- or amphetamine-based drugs induce chromosomal damage (structural aberrations, micronuclei, and sister chromatid exchanges) in peripheral blood lymphocytes of children with attention-deficit/hyperactivity disorder after 3 months of continuous treatment. METHOD: Stimulant drug-naïve subjects, 6 to 12 years of age, in good overall health, and judged to be appropriate candidates for stimulant therapy based on rigorously diagnosed ADHD using DSM-IV criteria, were randomized into two open-label treatment groups (methylphenidate or mixed amphetamine salts). Each subject provided a blood sample before initiation of treatment and after 3 months of treatment. Pretreatment and posttreatment frequencies of chromosomal aberrations, micronuclei, and sister chromatid exchanges were determined for each subject. RESULTS: Sixty-three subjects enrolled in the study; 47 subjects completed the full 3 months of treatment, 25 in the methylphenidate group and 22 in the amphetamine group. No significant treatment-related increases were observed in any of the three measures of cytogenetic damage in the 47 subjects who completed treatment or the 16 subjects who did not. CONCLUSIONS: Earlier findings of methylphenidate-induced chromosomal changes in children were not replicated in this study. These results add to the accumulating evidence that therapeutic levels of methylphenidate do not induce cytogenetic damage in humans. Furthermore, our results indicate that amphetamine-based products do not pose a risk for cytogenetic damage in children.
Subject(s)
Amphetamines/toxicity , Attention Deficit Disorder with Hyperactivity/drug therapy , Central Nervous System Stimulants/toxicity , Chromosome Aberrations , Methylphenidate/toxicity , Micronucleus Tests , Sister Chromatid Exchange , Amphetamines/therapeutic use , Attention Deficit Disorder with Hyperactivity/genetics , Central Nervous System Stimulants/therapeutic use , Child , Dose-Response Relationship, Drug , Female , Humans , Lymphocytes/drug effects , Lymphocytes/metabolism , Male , Methylphenidate/therapeutic useABSTRACT
OBJECTIVE: The purpose of this study was to assess the effectiveness and tolerability of atomoxetine during acute treatment of attention-deficit/hyperactivity disorder (ADHD) in 5 and 6 year olds. METHOD: Twenty two children (male n = 19, 86%) with ADHD were treated with atomoxetine for 8 weeks in a three-site, open-label pilot study. Dosing was flexible, with titration to a maximum of 1.8 mg/kg per day. Parent education on behavior management was provided as part of each pharmacotherapy visit. RESULTS: Subjects demonstrated a mean decrease of 20.68 points (SD = 12.80, p < 0.001)) on the ADHD Rating Scale-IV (ADHD-IV-RS) total score, 10.18 (SD = 7.48, p < 0.001) on the inattentive subscale and 10.50 (SD = 7.04, p < 0.001) on the hyperactive/impulsive subscale. Clinical Global Impression-Severity (CGI-S) was improved in 82% of the children (95% CI, 66-98%) and Children's Global Assessment (CGAS) scores improved 18.91 points on average (SD = 12.20, p < 0.001). The mean final dose of atomoxetine was 1.25 mg/kg per day (SD = 0.35 mg/kg per day). Mood lability was the most commonly reported adverse event (n = 12, 54.5%). Eleven subjects (50%) reported decreased appetite and a mean weight loss of 1.04 kg (SD = 0.80 kg) (p < 0.001) was observed for the group. Vital sign changes were mild and not clinically significant. There were no discontinuations due to adverse events or lack of efficacy. CONCLUSION: Atomoxetine was generally effective for reducing core ADHD symptoms in the 5 and 6 year olds in this open-label study.
