Kratom exposures reported to United States poison control centers: 2011-2017.

Context: Kratom, or Mitragyna speciosa, is a plant indigenous to Southeast Asia that has gained national attention in the United States for its increased use in the self-management of opioid withdrawal and pain, as well as for concerns about its safety. Methods: This study analyzes exposures to kratom reported to poison control centers (PCCs) in the United States during 2011-2017 from the National Poison Data System (NPDS). Discussion: From 2011 through 2017, 1807 kratom exposures were reported to United States PCCs. Almost two-thirds (65.0%) of these exposures occurred during 2016-2017. Most exposures occurred among adults ≥20 years (88.9%), males (70.8%), at a residence (86.1%), and were intentional (74.3%). Among first-ranked kratom exposures, 31.8% resulted in admission to a health care facility (HCF) and 51.9% in a serious medical outcome. Multiple-substance exposures were associated with greater odds of admission to a HCF (OR: 2.80; 95% CI: 2.21-3.55) and a serious medical outcome (OR: 2.25; 95% CI: 1.77-2.85) compared with single-substance exposures. There were 11 deaths associated with kratom exposure, including two that occurred after exposure to kratom only. Among kratom-only exposures, 86.1% resulted in one or more clinical effects. The most common clinical effects were agitation/irritability (22.9%) and tachycardia (21.4%). There were seven neonatal exposures, including five experiencing withdrawal. Conclusions: Kratom is associated with a variety of serious medical outcomes, especially when used with other substances. More research is needed to define the human response to kratom. Increased regulation of kratom products would help guarantee product quality and safety. Individuals who choose to use kratom should be educated about its potential risks, including the dangers of using it in combination with other substances.

Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.

INTRODUCTION: There is increasing evidence that the pathophysiological target of mercury is in fact selenium, rather than the covalent binding of mercury to sulfur in the body's ubiquitous sulfhydryl groups. The role of selenium in mercury poisoning is multifaceted, bidirectional, and central to understanding the target organ toxicity of mercury. METHODS: An initial search was performed using Medline/PubMed, Toxline, Google Scholar, and Google for published work on mercury and selenium. These searches yielded 2018 citations. Publications that did not evaluate selenium status or evaluated environmental status (e.g., lake or ocean sediment) were excluded, leaving approximately 500 citations. This initial selection was scrutinized carefully and 117 of the most relevant and representative references were selected for use in this review. Binding of mercury to thiol/sulfhydryl groups: Mercury has a lower affinity for thiol groups and higher affinity for selenium containing groups by several orders of magnitude, allowing for binding in a multifaceted way. The established binding of mercury to thiol moieties appears to primarily involve the transport across membranes, tissue distribution, and enhanced excretion, but does not explain the oxidative stress, calcium dyshomeostasis, or specific organ injury seen with mercury. Effects of mercury on selenium and the role this plays in the pathophysiology of mercury toxicity: Mercury impairs control of intracellular redox homeostasis with subsequent increased intracellular oxidative stress. Recent work has provided convincing evidence that the primary cellular targets are the selenoproteins of the thioredoxin system (thioredoxin reductase 1 and thioredoxin reductase 2) and the glutathione-glutaredoxin system (glutathione peroxidase). Mercury binds to the selenium site on these proteins and permanently inhibits their function, disrupting the intracellular redox environment. A number of other important possible target selenoproteins have been identified, including selenoprotein P, K, and T. Impairment of the thioredoxin and glutaredoxin systems allows for proliferation intracellular reactive oxygen species which leads to glutamate excitosis, calcium dyshomeostasis, mitochondrial injury/loss, lipid peroxidation, impairment of protein repair, and apoptosis. Methylmercury is a more potent inhibitor of the thioredoxin system, partially explaining its increased neurotoxicity. A second important mechanism is due to the high affinity of mercury for selenium and the subsequent depletion of selenium stores needed for insertion into de novo generation of replacement selenoproteins. This mercury-induced selenium deficiency state inhibits regeneration of the selenoproteins to restore the cellular redox environment. The effects of selenium on mercury and the role this plays in biological response to mercury: Early research suggested selenium may provide a protective role in mercury poisoning, and with limitations this is true. The roles selenium plays in this reduction of mercury toxicity partially depends on the form of mercury and may be multifaceted including: 1) facilitating demethylation of organic mercury to inorganic mercury; 2) redistribution of mercury to less sensitive target organs; 3) binding to inorganic mercury and forming an insoluble, stable and inert Hg:Se complex; 4) reduction of mercury absorption from the GI tract; 5) repletion of selenium stores (reverse selenium deficiency); and 6) restoration of target selenoprotein activity and restoring the intracellular redox environment. There is conflicting evidence as to whether selenium increases or hinders mercury elimination, but increased mercury elimination does not appear to be a major role of selenium. Selenium supplementation has been shown to restore selenoprotein function and reduce the toxicity of mercury, with several significant limitations including: the form of mercury (methylmercury toxicity is less responsive to amelioration) and mercury dose. CONCLUSIONS: The interaction with selenium is a central feature in mercury toxicity. This interaction is complex depending on a number of features such as the form of mercury, the form of selenium, the organ and dose. The previously suggested "protective effect" of selenium against mercury toxicity may in fact be backwards. The effect of mercury is to produce a selenium deficiency state and a direct inhibition of selenium's role in controlling the intracellular redox environment in organisms. Selenium supplementation, with limitations, may have a beneficial role in restoring adequate selenium status from the deficiency state and mitigating the toxicity of mercury.

An Increase in Dietary Supplement Exposures Reported to US Poison Control Centers.

INTRODUCTION: The objective of this study was to investigate the epidemiology of dietary supplement exposures in the USA. METHODS: A retrospective analysis was conducted of out-of-hospital dietary supplement exposures reported to the National Poison Data System from 2000 through 2012. RESULTS: There were 274,998 dietary supplement exposures from 2000 through 2012. The annual rate of dietary supplement exposures per 100,000 population increased by 46.1% during 2000-2002, decreased 8.8% during 2002-2005, and then increased again by 49.3% from 2005 to 2012. These trends were influenced by the decrease in ma huang exposures starting in 2002. Miscellaneous dietary supplements accounted for 43.9% of all exposures, followed by botanicals (31.9%), hormonal products (15.1%), and other supplements (5.1%). The majority of dietary supplement exposures (70.0%) occurred among children younger than 6 years old and were acute (94.0%) and unintentional (82.9%). Serious medical outcomes accounted for 4.5% of exposures and most (95.0%) occurred among individuals 6 years and older. Ma huang products, yohimbe, and energy products were the categories associated with the greatest toxicity. CONCLUSIONS: There was an overall increase in the rate of dietary supplement exposures from 2000 through 2012. Although the majority of these exposures did not require treatment at a health care facility or result in serious medical outcomes, exposures to yohimbe and energy products were associated with considerable toxicity. Our results demonstrate the success of the FDA ban on ma huang products and the need for FDA regulation of yohimbe and energy products in the USA.

Two fatal cases of selenium toxicity.

Two patients, a 36-year-old female and a 36-year-old male, separately experienced new onset nausea, vomiting, diarrhea, abdominal pain, muscle weakness and pallor. Over a period of 14-16 h these symptoms continue and progress to include hypotension refractory to therapy, pulmonary edema and cardiovascular collapse. Autopsies show hemorrhagic pulmonary edema, splenomegaly and lack of anatomical cause for sudden death. Postmortem analysis, in one case post-embalming and exhumation, revealed elevated selenium concentrations and a determination of the cause of death. These two cases present several important features associated with selenium toxicity, two of which are previously unreported: (1) selenium as a potential homicidal agent, (2) the toxidrome and time frame of selenium toxicity, (3) selenium determination in exhumed, embalmed tissues, (4) postmortem urinary selenium concentration, and (5) decrease in tissue concentrations over time.

Acute selenium poisoning: suicide by ingestion.

Selenium is a ubiquitous element in the environment essential to the human diet and widely utilized in industrial processes. Fatal human selenium intoxication is rare. The authors report a case in which investigators recovered a bottle of gun-bluing agent beside a 24-year-old man. He exhibited signs and symptoms typical of acute selenium intoxication presenting with nausea and vomiting, followed by pulmonary edema and rapid cardiovascular collapse approximately 3 to 4 h after ingestion. Classic electrocardiographic (EKG) changes, which have been reported to occur in acute selenium intoxication, included sinus tachycardia with ST wave alteration. Toxicological results confirmed elevated blood and tissue concentrations. The cause of death was ascribed to acute selenium intoxication, which ensued rapidly after oral consumption. The manner of death was suicide. This case report, which presents an overview of acute and chronic selenium poisoning, underscores the value of thorough toxicologic analyses of tissue and body fluids in humans.

Dermal absorption of a liquid diphacinone rodenticide causing coagulaopathy.

Rare cases of coagulaopathies from dermal absorption of hydroxycoumarin derivatives have been reported. We report the first case of dermal absorption of an indandione derivative rodenticide causing severe coagulopathy. An 18-y-o male worker at a pest exterminating company spilled a concentrated liquid preparation of 0.106% diphacinone in his boot. He did not remove the boot or wash the area for 6 to 8 h. Seven days later he presented to the emergency department with flank pain, hematuria and epistaxis. Laboratory values were PT > 40 sec, PTT > 90, Hb 16.2, and platelets 273. Urinalysis reported gross hematuria with RBCs too numerous to count. Prolonged bleeding was noted at i.v. puncture sites. Initial therapy included i.m. injection of vitamin K and nasal packing. The patient's religious beliefs precluded the use of blood products. The patient was admitted for observation until PT was controlled. He was discharged on high dose vitamin K p.o. dose titrated to the international normalized ratio measured every 48 h. After 2 w, a dose of 100 mg vitamin K/d was set and the patient was followed as an outpatient for 3 mo. Vitamin K therapy was tapered and discontinued 60 d post-exposure with no further elevation in PT. Diphacinone was detected in a serum sample drawn 60 d post-exposure using gradient and isocratic HPLC methods with fluorescence and UV detection. Factors increasing the dermal absorption of the diphacinone were: prolonged skin contact in a confined area and exposure to a concentrated solution.

Skin breakdown and blisters from senna-containing laxatives in young children.

BACKGROUND: At the direction of the Food and Drug Administration, phenolphthalein was removed from all over-the-counter laxatives in 1999. Phenolphthalein was then replaced in most laxative products with the natural product senna from Cassia acutifolia Delile, which contains various anthraquinones. No data are available on the safety of senna use in children <6 years of age. OBJECTIVE: To describe the clinical outcomes of exposure to unintentional ingestion of senna-containing laxatives in young children. METHODS: All ingestion exposures of senna-containing laxatives in children <5 years of age from 6 poison centers over a 9-month period were evaluated. Inclusion criteria required 24-hour follow-up and the presence of diarrhea to confirm ingestion. Parents were told routinely that severe diaper rash was possible and to protect the perianal area with frequent cleansing and a barrier ointment if the child was wearing diapers. RESULTS: During the study period, 111 cases were reported: 19 children experienced no diarrhea, 4 were lost to follow-up, and 88 exposures were evaluated. Fifty-two children (59%) were