title: Plasma and urine dimercaptopropanesulfonate concentrations after dermal application of transdermal DMPS (TD-DMPS).
abstract: 2,3-Dimercaptopropane-1-sulfonate (DMPS) is a metal chelator approved in Europe for oral or intravenous use for heavy metal poisoning. Transdermally applied DMPS (TD-DMPS) is used by some alternative practitioners to treat autism, despite the absence of evidence for its efficacy. We found no literature evaluating the pharmacokinetics of the transdermal route of delivery or the ability of TD-DMPS to enhance urinary mercury elimination. We hypothesized that TD-DMPS is not absorbed. Eight adult volunteers underwent application of 1.5-3 drops/kg of TD-DMPS. Subjects provided 12-h urine collections the day before and day of application. Subjects underwent blood draws at 0, 30, 60,90, 120, and 240 min after TD-DMPS application. Plasma and urine were assayed for the presence of DMPS. Urine was assayed for any change in urinary mercury excretion after DMPS. One control subject ingested 250 mg of oral DMPS and underwent the same urine and blood collections and analyses. No subject had detectable urine DMPS or increased urine mercury excretion after TD-DMPS. One subject had detectable levels of DMPS in the 30-min plasma sample, suspected to be contamination. All other samples for that subject and the other seven subjects showed no detectable plasma DMPS. The control subject had detectable urine and plasma DMPS levels and increased urine mercury excretion. These results indicate that TD-DMPS is not absorbed. There was no increase in urine mercury excretion after TD-DMPS. Our results argue that TD-DMPS is an ineffective metal chelator.
authors.affiliation: Department of Medical Toxicology, Banner Good Samaritan Medical Center, Medical Toxicology, Phoenix, AZ 85006, USA.
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Cohen
authors.forename: Anne-Michelle
authors.initials: AM
authors.lastname: Ruha
authors.forename: Steven C
authors.initials: SC
authors.lastname: Curry
authors.forename: Kallol
authors.initials: K
authors.lastname: Biswas
authors.forename: Benjamin
authors.initials: B
authors.lastname: Westenberger
authors.forename: Wei
authors.initials: W
authors.lastname: Ye
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: Caldwell
authors.forename: Frank
authors.initials: F
authors.lastname: Lovecchio
authors.forename: Keith
authors.initials: K
authors.lastname: Burkhart
authors.forename: Nasr
authors.initials: N
authors.lastname: Samia
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000328:Adult; D002614:Chelating Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D008297:Male; D017669:Mercury Compounds / Q000652:urine; D008875:Middle Aged; D014494:Unithiol / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D002614:Chelating Agents; D017669:Mercury Compounds; D014494:Unithiol