Toxicology
Anthony FT Brown, Michael D Cadogan in Emergency Medicine, 2020
Start aggressive fluid resuscitation in patients with signs of gastrointestinal or systemic toxicity, and institute decontamination and chelation measures. Discuss these with the senior ED doctor or a clinical toxicologist: Decontamination: do not administer charcoal or attempt to induce vomitingperform whole bowel irrigation if there are significant numbers of tablets beyond the pylorus.Chelation therapy: start a desferrioxamine infusion at 2 mg/kg per h and rapidly increase to 15 mg/kg per h in severe casesreduce the infusion rate if hypotension occurs.
Aspects of Nickel Allergy: Epidemiology, Etiology, Immune Reactions, Prevention, and Therapy
Jurij J. Hostýnek, Howard I. Maibach in Nickel and the Skin, 2019
In cases of extremely hypersensitive patients, an alternative therapeutic approach to using antiinflammatory topical corticoids is the systemic administration of chelating agents such as tetraethylthiuramdisulfide (TETD, Antabuse, disulfiram), DDC, or triethylenetetramine. It only yields limited success, however; the dermatitis is not completely suppressed or resumes after cessation of treatment. Eleven patients whose NAH status was confirmed by oral nickel dosing were given 100 mg TETD tablets orally over 2 months. In some of the patients dermatitis cleared, but skin flares reappeared when treatment was discontinued (Kaaber et al., 1979). A similar course and outcome of chelation therapy with a daily oral dose of 200 mg disulfiram over 8 weeks was reported by Christensen. Although in 11 patients with pompholyx the condition resolved and 8 showed partial improvement, relapse occurred in all patients within weeks after treatment was discontinued (Christensen and Kristensen, 1982). TETD and DDC given orally brought relief in nickel dermatitis only as long as dosing continued (Menné and Kaaber, 1978). TETD given orally caused a measurable rise in serum and urinary nickel levels, suggesting that preexisting nickel deposits are mobilized and excreted by chelation (Christensen, 1982b; Christensen and Kristensen, 1982; Kaaber et al., 1979; Menné et al., 1980). Chelating drugs given systemically were reported to produce toxic side effects, however (Spruit et al., 1978). TETD caused lassitude in patients (Kaaber et al., 1979) and hepatotoxicity (Kaaber et al., 1987).
Metals
Frank A. Barile in Barile’s Clinical Toxicology, 2019
Toxicity from metals and metallic elements depends largely on the route of exposure (inhalation, dermal, or oral), chemical species (inorganic, organic, or gaseous state), concentration, frequency, and duration. The management of toxicity generally entails instituting the ABCs of emergency treatment (see Chapter 3). In the case of a few chemical agents, antidotes are available for neutralizing, eliminating, or ameliorating the effects of metal exposure. Chelation therapy is generally associated with the treatment of metal poisoning for the particular goal of decreasing the body burden of the chemicals that have been absorbed and distributed to physiological compartments.* Chelators have one or more binding sites for particular compounds; their affinity varies according to their structure and properties.
Unregulated supplement use causing insidious lead toxicity
Published in Baylor University Medical Center Proceedings, 2023
Grant Manh-tri Pham, Anuj Sharma
New immigrants coming to America from all parts of the world bring their traditions and folk medicines with them. Immigration from India has increased along with ayurvedic supplement use.4 One study showed that at least a quarter of traditional medicine in India had lead levels above the World Health Organization recommended threshold.5 Another study showed that not only is lead contaminated in many of these ayurvedic supplements from South Asia, but also other heavy metals such as cadmium, arsenic, or mercury. Moreover, research from the Centers for Disease Control and Prevention showed 12 cases of lead-tainted ayurvedic in five states from 2000 to 2003. Case reports from a similar time frame concur with this assessment, with four individuals with lead intoxication due to ayurvedic supplementation. All presented to the emergency department with vague abdominal symptoms and lead levels >80 µg/dL. Chelation therapy was successfully initiated in those cases.7 Furthermore, a cross-sectional analysis using data from the National Health and Nutrition Examination Survey from 1999 to 2004 showed that participants using ayurvedic supplements had blood lead levels 24% higher than those of nonusers.8
Adherence to Iron Chelation Therapy among Adults with Thalassemia: A Systematic Review
Published in Hemoglobin, 2022
Margaret Locke, Paavani S. Reddy, Sherif M. Badawy
The main iron chelation agents include deferoxamine (DFO), deferiprone (DFP), and deferasirox (DFX). Due to poor oral bioavailibility, DFO is the only chelator that must be administered subcutaneously or intravenously up to once a day; DFP and DFX may be administered orally up to three times a day [10]. The known side effects associated with each chelator include infusion reactions in DFO, gastrointestinal distress, agranulocytosis in DFP [11], and transaminitis in DFP and DFX [10]. In addition, prior studies have suggested that the side effects of these chelators, the inconvenience of parenteral administration of DFO, frequency of DFP, and DFX administration, lead to reduced adherence to iron chelation regimens, and subsequently, poorer control over iron deposition in vital organs [12,13]. Prior studies have shown differences in the chelators’ ability to control iron load, such as the superiority of DFP in reducing myocardial iron load and DFO in reducing hepatic iron load [13]. Although data are limited, a recent cost analysis estimated that inadequate adherence to iron chelation regimens leads to numerous complications and associated lifetime costs of US$33,142.00 [12].
Mercury in natural health products as a cause of membranous nephropathy
Published in Baylor University Medical Center Proceedings, 2020
Stephen Tanner, Vivek Sharma, Deborah Jebakumar, Mohanram Narayanan, Arundhati Rao
Treatment of mercury-induced disease starts with discontinuation of inciting exposures. Chelation therapy has been shown to be a useful therapy that causes increased renal excretion with reduced time to resolution of symptoms.3,5 In our patient, chelation therapy was not given, as he was improving before the results of the 24-hour urine collection were available. He was started on cyclosporine due to the immune complex deposition and severe proteinuria; however, immunosuppression was weaned when the mercury results and final biopsy readings were available. He improved over the course of about 12 weeks after discontinuation of the offending agents. High serum levels of arsenic were present in blood and urine. Arsenic poisoning can lead to tubulointerstitial nephritis and acute tubular necrosis.7 In our patient, the renal biopsy did not show findings consistent with arsenic-related damage.
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