Arsenic Poisoning Chronic Clinical Trial
Official title:
Selenium and Arsenic Pharmacodynamics
This clinical trial should prove that selenium can treat arsenic exposure in humans by promoting excretion. The new trial differs from previous trials in that participants will be maintained in a local clinic and provided with food and water from their home villages. The purpose of this study to determine the fate of selenium supplements in feces, urine and blood of volunteers living in conditions of high arsenic load in drinking water. The use of a clinic will enable monitoring of all intake and excretion of both arsenic and selenium, and will ensure that participants take their selenium doses or placebo as appropriate. This proof of concept is absolutely essential groundwork for any remediation strategy involving selenium supplements.
Main Purpose:
Determine the fate of selenium supplements in feces, urine and blood through a new Phase I/II
clinical trial pharmacodynamics study in Bangladesh. This will include conventional analysis
of feces, urine and blood samples, tracing the fate of selenium by administering isotopically
enriched 77Se (a naturally occurring non-radioactive stable isotope). The use of 77Se will
allow us to discriminate between endogenous selenium already in the bodies of the trial
participants (patients) from the administered selenium given to the patients.
Clinical Trial Hypotheses:
- In a group of patients exhibiting symptoms of arsenicosis (chronic low-level arsenic
poisoning), a single, elevated dose of anhydrous sodium selenite leads to excretion of
arsenic at levels significantly higher than patients receiving placebo.
- In the selenite-supplemented (treatment) group, the total arsenic excreted is
significantly higher than that consumed in the diet and drinking water.
- In the treatment group, selenium co-excreting with arsenic originates from the
administered selenium supplement, rather than from endogenous selenium.
- The ratio of arsenic to selenium in the feces, urine and blood of the treatment group
following administration of the selenium supplement is approximately 1:1, consistent
with the formation of the discrete molecular entity, the seleno bis-S-glutathionyl
arsinium anion discovered in the investigators' earlier animal experiments.
The process to be followed:
A tightly controlled Phase I/II clinical trial in Bangladesh to prove that selenium can
remove arsenic from victims' bodies. 40 volunteer arsenicosis sufferers will be housed in a
local private in-patient clinic for 10 consecutive days. While in the clinic, they will
follow a fixed, communal diet consisting of drinking water and meals from their village. On
the 6th day in the clinic investigators will give a single dose of either placebo (table
salt, 0.8 mg) or anhydrous sodium selenite (0.8 mg selenium) labelled with a non-radioactive
naturally occurring isotope (77Se), to distinguish it from selenium already in the body.
Placebo and anhydrous sodium selenite look similar and taste very much alike. Placebo or
anhydrous sodium selenite will be supplied in a powdered form at the bottom of a glass and
diluted by 100 ml of purified water immediately before being ingested by participants under
close control by the clinical staff. The investigators will analyze arsenic and selenium
levels in feces, urine and blood samples before and after the dose, and will use molecular
speciation analyses to determine their chemical form in blood, urine and feces. Also,
investigators will analyze arsenic and selenium levels in finger- and toenails and hair at
the beginning of the trial as a possible biomarker of As exposure.
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| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Not yet recruiting |
NCT03893721 -
Effect of Chronic Arsenic Exposure on Malnutrition of Under Five Children
|