succimer and Child-Development-Disorders--Pervasive

It has been suggested that the severity of autism spectrum disorder (ASD) symptoms is positively correlated with the level of circulating or stored toxic metals, and that excretion of these heavy metals, brought about by the use of pharmaceutical chelating agents, results in improved symptoms.. To assess the potential benefits and adverse effects of pharmaceutical chelating agents (referred to as chelation therapy throughout this review) for autism spectrum disorder (ASD) symptoms.. We searched the following databases on 6 November 2014: CENTRAL, Ovid MEDLINE, Ovid MEDLINE In-Process, Embase,PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and 15 other databases, including three trials registers. In addition we checked references lists and contacted experts.. All randomised controlled trials of pharmaceutical chelating agents compared with placebo in individuals with ASD.. Two review authors independently selected studies, assessed them for risk of bias and extracted relevant data. We did not conduct a meta-analysis, as only one study was included.. We excluded nine studies because they were non-randomised trials or were withdrawn before enrolment.We included one study, which was conducted in two phases. During the first phase of the study, 77 children with ASD were randomly assigned to receive seven days of glutathione lotion or placebo lotion, followed by three days of oral dimercaptosuccinic acid (DMSA). Forty-nine children who were found to be high excreters of heavy metals during phase one continued on to phase two to receive three days of oral DMSA or placebo followed by 11 days off, with the cycle repeated up to six times. The second phase thus assessed the effectiveness of multiple doses of oral DMSA compared with placebo in children who were high excreters of heavy metals and who received a three-day course of oral DMSA. Overall, no evidence suggests that multiple rounds of oral DMSA had an effect on ASD symptoms.. This review included data from only one study, which had methodological limitations. As such, no clinical trial evidence was found to suggest that pharmaceutical chelation is an effective intervention for ASD. Given prior reports of serious adverse events, such as hypocalcaemia, renal impairment and reported death, the risks of using chelation for ASD currently outweigh proven benefits. Before further trials are conducted, evidence that supports a causal link between heavy metals and autism and methods that ensure the safety of participants are needed.

Topics: Administration, Oral; Chelating Agents; Chelation Therapy; Child; Child Development Disorders, Pervasive; Child, Preschool; Female; Glutathione; Humans; Male; Metals, Heavy; Randomized Controlled Trials as Topic; Skin Cream; Succimer

To address a possible environmental contribution to autism, we carried out a retrospective study on urinary porphyrin levels, a biomarker of environmental toxicity, in 269 children with neurodevelopmental and related disorders referred to a Paris clinic (2002-2004), including 106 with autistic disorder. Urinary porphyrin levels determined by high-performance liquid chromatography were compared between diagnostic groups including internal and external control groups. Coproporphyrin levels were elevated in children with autistic disorder relative to control groups. Elevation was maintained on normalization for age or to a control heme pathway metabolite (uroporphyrin) in the same samples. The elevation was significant (P < 0.001). Porphyrin levels were unchanged in Asperger's disorder, distinguishing it from autistic disorder. The atypical molecule precoproporphyrin, a specific indicator of heavy metal toxicity, was also elevated in autistic disorder (P < 0.001) but not significantly in Asperger's. A subgroup with autistic disorder was treated with oral dimercaptosuccinic acid (DMSA) with a view to heavy metal removal. Following DMSA there was a significant (P = 0.002) drop in urinary porphyrin excretion. These data implicate environmental toxicity in childhood autistic disorder.

Topics: Administration, Oral; Adolescent; Autistic Disorder; Biomarkers; Chelating Agents; Child; Child Development Disorders, Pervasive; Child, Preschool; Chromatography, High Pressure Liquid; Coproporphyrins; Environmental Exposure; Female; Heavy Metal Poisoning; Humans; Male; Metals, Heavy; Porphyrias; Porphyrins; Retrospective Studies; Succimer; Treatment Outcome; Uroporphyrins

To investigate the observation that children with pervasive developmental disorders have later and more prolonged lead exposure and are more likely to be reexposed when compared to lead-poisoned children without pervasive developmental disorders.. Retrospective chart review.. A large, urban lead treatment program.. Over a six year period 17 children with pervasive developmental disorders (including autism) were treated. Compared to a randomly selected group of 30 children without pervasive developmental disorders who were treated for plumbism over the sam interval, those with pervasive developmental delay were significantly older at diagnosis (46.5 vs 30.3 months, p = .03) and had a longer period of elevated blood lead levels (39.1 vs 14.1 months, p = .013) during management. Despite close monitoring, state-mandated environmental inspection and prompt lead hazard reduction or alternative housing, 75% of children with pervasive developmental disorders were reexposed to lead during medical management compared with 23% of children without pervasive developmental disorders (p = .001).. 1) lead intoxication among children with pervasive developmental disorders may appear de novo beyond the third year of life and is associated with a high rate of reexposure; 2) the provision of deleaded housing (by current techniques) may not be sufficient to protect these children from repeated lead exposure; 3) these data support recommendations by the Centers for Disease Control that children with developmental delays be closely monitored for the appearance of lead intoxication. This monitoring should continue beyond the third year of life.

Topics: Chelating Agents; Child Development Disorders, Pervasive; Child, Preschool; Environmental Exposure; Humans; Lead Poisoning; Penicillamine; Pica; Recurrence; Retrospective Studies; Succimer