Journal of Medical Toxicology

, Volume 9, Issue 4, pp 318–325 | Cite as

Recommendations for Provoked Challenge Urine Testing

  • Anne-Michelle RuhaEmail author


“Urine mobilization test,” “challenge test,” and “provoked urine test” are all terms used to describe the administration of a chelating agent to a person prior to collection of their urine to test for metals. There is no standard, validated challenge test. Despite recommendations by professional and government organizations against the use of provoked urine testing, the tests are still commonly used and recommended by some practitioners. Challenge testing utilizes a variety of chelating agents, including dimercaptosuccinic acid (DMSA), dimercaptopropanesulfonate (DMPS), and ethylenediaminetetraacetic acid (EDTA). The agents are given by a variety of routes of administration, doses used are inconsistent, and urine collection procedures vary. Additional problems with challenge tests include comparison of results to inappropriate reference ranges and creatinine correction of urine obtained within hours of chelator administration. Human volunteer studies demonstrate that mercury is detected in the urine of most people even in the absence of known exposure or chelator administration, and that urinary mercury excretion rises after administration of a chelator, regardless of exposure history and in an unpredictable fashion. Studies also demonstrate that challenge testing fails to reveal a “body burden” of mercury due to remote exposure. Chelating agents have been associated with adverse reactions. Current evidence does not support the use of DMPS, DMSA, or other chelation challenge tests for the diagnosis of metal toxicity. Since there are no established reference ranges for provoked urine samples in healthy subjects, no reliable evidence to support a diagnostic value for the tests, and potential harm, these tests should not be utilized.


Provoked urine test Challenge test Urine mobilization test Metal chelation 


Conflict of interest

For the work under consideration for publication, Dr. Ruha received an honorarium (which she donated to MTF) and reimbursement for travel through the ACMT/ATSDR Cooperative Agreement. As relevant financial activities outside the submitted work, Dr. Ruha is a BTG and RDT paid speaker.


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Copyright information

© American College of Medical Toxicology 2013

Authors and Affiliations

  1. 1.Department of Medical Toxicology, Banner Good Samaritan Medical Center, Center for Toxicology and Pharmacology Education and ResearchUniversity of Arizona College of MedicinePhoenixUSA

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