NALTREXONE PLASMA-LEVELS, CLINICAL-RESPONSE AND EFFECT ON WEIGHT IN AUTISTIC-CHILDREN

This research measured naltrexone levels in plasma, to assess the rela tionship between behavioral response to naltrexone and plasma levels, and the effects of naltrexone on weight in hospitalized autistic child ren (n = 41). A double-blind, placebo-controlled, parallel groups desi gn with fixed dose was used, with random assignment to naltrexone or p lacebo. Drug plasma levels were analyzed by gas chromatography/mass sp ectrometry, and weights were obtained weekly. Naltrexone levels measur ed in 17 children ranged from 0.12 to 5.60 ng/mL (mean = 0.71, standar d error of the mean = 0.32). There was no relationship between plasma levels and age, level of intellectual functioning, scores on the 14 se lected Children's Psychiatric Rating Scale (CPRS) items, Clinical Glob al Impressions, Global Clinical Consensus, and the CPRS hyperactivity factor. There was a trend (p = .06) for children receiving naltrexone in the highest weight percentile (greater than or equal to 90th) to lo se weight (mean = -0.42 kg) but this was not the case for those in the lower weight percentiles (mean = +0.03 kg).