Mercury Chelation to Treat Autism

• Status: Withdrawn
• Trial end date: 2007-03-01
• Target enrollment: 0
• Participant gender: All

Summary

This study will examine whether DMSA, an oral chelating agent that removes mercury and other metals from the body, is beneficial for children with autism. DMSA is commonly used to treat autism, although it has never been tested in a controlled study and there is no proof that it helps children with the disorder. Support for its use is based on single-case reports of benefits of chelation with DMSA. This study will help determine whether or not DMSA is useful for treating autism.

Children between 4 and 10 years of age with autism spectrum disorder who weigh at least 33 pounds, who have detectable, but not toxic, levels of mercury or lead in the blood, and who have not previously received chelation therapy may be eligible for this study.

Participants complete a medical history, behavioral and psychological assessment and physical examination. Blood, hair, urine and stool samples are collected for testing.

Because DMSA can remove minerals the body needs, such as zinc and iron, as well as the toxic lead and mercury, participants take a daily multivitamin supplement starting 1 month before beginning chelation therapy and continuing for the duration of treatment. After 1 month of the supplementation regimen, the children are assigned to receive DMSA or placebo for 12 weeks, divided into six 2-week cycles. They take the assigned drug 3 times a day on days 1, 2 and 3 of each cycle and continue the multivitamin every day.

The children are seen in the clinic immediately before and after the first, third and sixth cycles. At each checkup, the parent or guardian answers a set of questions about the child's autism symptoms, physical health and medication side effects. Blood, urine and stool samples are collected for laboratory testing.

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• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: National Institute of Mental Health (NIMH)

Criteria

• INCLUSION CRITERIA:

Subjects may be included in the study only if they meet all of the following criteria:

• Male or female subjects, four to ten years of age.

• Meets research criteria for ASD (specifically, autism, Asperger Disorder, or Pervasive Developmental Disorder - Not Otherwise Specified).

• Detectable (greater than 0.1 microgram per deciliter) levels of blood lead and/or blood mercury.

• Each legal guardian must have a level of understanding sufficient to agree to all required tests and examinations. Each legal guardian must understand the nature of the study and must provide written consent to study protocol.

EXCLUSION CRITERIA:

• History of allergic reaction to sulfur or thiol-containing substances

• History of previous chelation therapy for autism

• History of uncontrolled epilepsy

• Weight less than 15 kg at screening

• Presence of a chronic medical condition that might interfere with study participation in which study participation would be contraindicated or in which there may be clinically significant abnormal baseline laboratory results.

• Level of lead above 10 microgram per d, or level of mercury over 44 microgram per deciliter (toxic levels that require intervention with chelation and preclude placebo assignment) or other evidence of heavy metal toxicity.

• Recent (less than two months prior to study entry) initiation of behavior therapy