Chelation and Autism Ranking:

Risks and Safety

Hazards

According to Davis et al (2013)

“The chemical substances utilized in chelation treatment have a myriad of potential and potentially serious, side effects, including fever, vomiting, diarrhea, loss of appetite, hypertension, hemorrhoid symptoms, metallic taste, hypotension, cardiac arrhythmias, hypocalcemia, the latter of which can in turn cause fatal cardiac arrest.  In 2005, for example, a 5-year-old boy with ASD died from cardiac arrest caused by hypocalcemia while receiving intravenous chelation. The potential safety risks associated with chelation recently resulted in a suspension of a clinical study of chelation treatment for autism. Additional safety issues arose from a rodent study that found lasting cognitive impairment.”

According to the American College of Medical Toxicology (2009) even some forms of testing for metal toxicity are potentially harmful.

“It is ... the position of the American College of Medical Toxicology that post-challenge urinary metal testing has not been scientifically validated, has no demonstrated benefit, and may be harmful when applied in the assessment and treatment of patients in whom there is concern for metal poisoning.”

Specific chelators

• Alpha lipoic acid: According to the University of Maryland Medical Center (2014), side effects are generally rare and may include insomnia, fatigue, diarrhea, and skin rash.
• DMSA:  According to Flora and Pachauri (2010), “Adverse reaction of DMSA includes gastrointestinal discomfort, skin reaction, mild neutropenia and elevated liver enzymes.” According to Defeat Autism Now! (2005) “Serious side effects of DMSA are extremely rare and include allergic reaction, toxic epidermal necrolysis (TEN) and erythema multiforme (Stevens-Johnson syndrome). Potentially dangerous neutropenia and thrombocytopenia may also occur.”
• DMPS: According to Flora and Pachauri (2010), “Adverse reactions during treatment with DMPS include gastrointestinal discomfort, skin reactions, mild neutropenia, and elevated liver enzymes.” However, Van Der Linde et al (2008) reported that DMPS had caused Stevens-Johnson syndrome in one child and they concluded that “… chelation therapy with DMPS is not harmless medication; it can have serious side effect and should therefore only be used in patients with proven intoxication.”
• EDTA: According to Flora and Pachauri (2010), “The risks associated with CaNa2EDTA therapy are substantial, including renal failures, arrhythmias, tetany, hypocalcaemia, hypotension, bone marrow depression, prolonged bleeding time, convulsions, respiratory arrest, etc.”
• N-Acetyl-L-cysteine: According to the University of Maryland Medical Center (2014), toxic forms of cysteine that should be avoided include D-cysteine, D-cystine, 5-methyl cysteine.  Very high doses (more than 7 grams) of cysteine may be toxic to human cells and may even lead to death. Taking NAC by mouth may cause nausea, vomiting, and diarrhea.
• TTFD: According to the WebMD website, accessed on 5 August 2016, “Thiamine is likely safe when taken by mouth in appropriate amounts, although rare allergic reactions and skin irritation have occurred”.
• Zeolite: According to the Memorial Sloan Kettering Cancer Center (2016), some forms of airborne zeolite [a form of zeolite unlikely to be used as a chelator] can cause fibrosis, pneumoconiosis and mesothelioma,

Contraindications

There are a number of contraindications (something which makes a particular treatment or procedure potentially inadvisable) for different groups of people. For example

• Alpha lipoic acid: According to the University of Maryland Medical Center (2014), alpha-lipoic acid has not been studied in children, so it is not recommended for pediatric use. In addition, alpha lipoic acid should only be used under careful medical supervision in people with certain medical conditions (such as diabetes) or who are taking certain medications (such as those used in chemotherapy).
• DMSA:  We have been unable to identify any contraindications for DMSA.
• DMPS: According to the Trace Minerals International Laboratory website, accessed on 3 August 2016, DMPS should only be used under careful medical supervision in people with reduced kidney function, in people with hypersensitivity to DMPS and in people with some allergies or with asthma.
• EDTA: According to the WebMD website, accessed on 3 August 2016, EDTA should not be used in people who are taking certain medications (such as insulin and wafarin) and should only be used under careful medical supervision in people using diuretic medications [increase urine].  EDTA should only be used under careful medical supervision in people with specific medical conditions such as asthma, epilepsy and heart problems.
• N-Acetyl-L-cysteine: According to the University of Maryland Medical Center (2014), NAC should only be used under careful medical supervision in people with some heart conditions, in people with cystinuria and in people with asthma.
• TTFD: According to the WebMD website, accessed on 5 August 2016, there are no known contraindications for TTFD.
• Zeolite: According to the Memorial Sloan Kettering Cancer Center (2016), you should not take zeolite if you are taking any medications especially if you are a transplant patient and/or taking drugs to suppress the immune system, if you are taking drugs as part of chemotherapy, you are using antibiotics or drugs that contain iron.

Explanation of terms

Arrhythmias (disturbed heart rhythm); cystinuria ( kidney condition); erythema multiforme aka Stevens-Johnson syndrome (potentially fatal skin condition), fibrosis (increase in fibrous tissue); hypocalcemia (low calcium serum levels in the blood; hypertension (low blood pressure); mesothelioma (cancer of the lining of the organs in the body); neutropenia (low levels of a type of blood cell);  pneumoconiosis (respiratory disease); tetany (intermittent muscular spasms); thrombocytopenia  (low amount of blood platelets); toxic epidermal necrolysis (potentially fatal skin condition).

Updated

16 Jun 2022

Last Review

01 Dec 2016

Next Review

01 Apr 2023