Mercury Toxicity - Treatment

Treatment

Identifying and removing the source of the mercury is crucial. Decontamination requires removal of clothes, washing skin with soap and water, and flushing the eyes with saline solution as needed. Inorganic ingestion such as mercuric chloride should be approached as the ingestion of any other serious caustic. Immediate chelation therapy is the standard of care for a patient showing symptoms of severe mercury poisoning or the laboratory evidence of a large total mercury load.

Chelation therapy for acute inorganic mercury poisoning can be done with DMSA, 2,3-dimercapto-1-propanesulfonic acid (DMPS), D-penicillamine (DPCN), or dimercaprol (BAL). Only DMSA is FDA-approved for use in children for treating mercury poisoning. However, several studies found no clear clinical benefit from DMSA treatment for poisoning due to mercury vapor. No chelator for methylmercury or ethylmercury is approved by the FDA; DMSA is the most frequently used for severe methylmercury poisoning, as it is given orally, has fewer side-effects, and has been found to be superior to BAL, DPCN, and DMPS. Alpha-lipoic acid (ALA) has been shown to be protective against acute mercury poisoning in several mammalian species when it is given soon after exposure; correct dosage is required, as inappropriate dosages increase toxicity. Although it has been hypothesized that frequent low dosages of ALA may have potential as a mercury chelator, studies in rats have been contradictory. Glutathione and N-acetylcysteine (NAC) are recommended by some physicians, but have been shown to increase mercury concentrations in the kidneys and the brain. Experimental findings have demonstrated an interaction between selenium and methylmercury, but epidemiological studies have found little evidence that selenium helps to protect against the adverse effects of methylmercury.

Even if the patient has no symptoms or documented history of mercury exposure, a minority of physicians (predominantly those in alternative medicine) use chelation to "rid" the body of mercury, which they believe to cause neurological and other disorders. A common practice is to challenge the patient's body with a chelation agent, collect urine samples, and then use laboratory reports to diagnose the patient with toxic levels of mercury; often no pre-chelation urine sample is collected for comparison. The patient is then advised to undergo further chelation. No scientific data supports the claim that the mercury in vaccines causes autism or its symptoms, and there is no scientific support for chelation therapy as a treatment for autism.

Chelation therapy can be hazardous if administered incorrectly. In August 2005, an incorrect form of EDTA used for chelation therapy resulted in hypocalcemia, causing cardiac arrest that killed a five-year-old autistic boy.