UK childhood exposures to pesticides 2004-2007: a TOXBASE toxicovigilance study

Imaging Findings and Toxicological Mechanisms of Nervous System Injury Caused by Diquat

Diquat (DQ) is a nonselective bipyridine herbicide with a structure resembling paraquat (PQ). In recent years, the utilization of DQ as a substitute for PQ has grown, leading to an increase in DQ poisoning cases. While the toxicity mechanism of DQ remains unclear, it is primarily attributed to the intracellular generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) through the process of reduction oxidation. This results in oxidative stress, leading to a cascade of clinical symptoms. Notably, recent reports on DQ poisoning have highlighted a concerning trend: an upsurge in cases involving neurological damage caused by DQ poisoning. These patients often present with severe illness and a high mortality rate, with no effective treatment available thus far. Imaging findings from these cases have shown that neurological damage tends to concentrate on the brainstem. However, the specific mechanisms behind this poisoning remain unclear, and no specific antidote exists. This review summarizes the research progress on DQ poisoning and explores potential mechanisms. By shedding light on the nerve damage associated with DQ poisoning, we hope to raise awareness, propose new avenues for investigating the mechanisms of DQ poisoning, and lay the groundwork for the development of treatment strategies for DQ poisoning. Trial registration number: 2024PS174K.

Systematic differences between healthcare professionals and poison information staff in the severity scoring of pesticide exposures

CONTEXT

Severity scores are used in triage and for data comparison in cases of poisoning. Exposure severity scores have not been generally validated and their utilization by healthcare staff other than specialists in poison information (SPIs) is untested.

OBJECTIVE

To compare the poisoning severity grading allocated in pesticide exposure cases by healthcare professional enquirers and poison information staff.

METHODS

Pesticide exposures reported to the U.K. National Poisons Information Service (NPIS) systems in a prospective study were graded for severity by healthcare professional enquirers and NPIS SPIs who used established poisons severity-grading algorithms. The scores were compared in children and adults, for the two professional groupings, both overall and for separate pesticides.

RESULTS

Overall SPIs graded severity resulting from pesticide exposure at a lower level than the enquirer. For children, enquirer mean severity score was 1.62 (95% confidence interval (CI) 1.57-1.66) and SPIs mean severity score was 1.16 (95% CI 1.13-1.19) (p < 0.001). For adults, enquirer mean severity score was 1.91 (95% CI 1.84-1.97) and SPIs mean severity score was 1.74 (95% CI 1.69-1.79) (p < 0.001). Importantly, the differences in the scores between the two professional groups were greater in children [+0.46 (95% CI 0.41-0.51)] than in adults [+0.17 (95% CI 0.11-0.24)] (p < 0.001). Findings for individual pesticides were less consistent but in general showed similar trends. The exception was glyphosate for which severity grading by poison information staff was higher for children [SPIs 1.68 (95% CI 1.38-1.96) than the enquirers 1.26 (95% CI 1.08-1.44), p < 0.02].

CONCLUSIONS

Our findings suggest inherent differences in the perception of pesticide toxicity between healthcare professionals and SPIs. There was also a difference in the scoring approach depending on the pesticide involved. Additional investigations are required to define the role and accuracy of severity scoring in different types of poisoning and the applicability to different types of severity assessors.

Clinical characteristics of mephedrone toxicity reported to the U.K. National Poisons Information Service

Objective

To describe the patterns and clinical features of toxicity related to recreational use of mephedrone and other cathinones in the UK using data collected by the National Poisons Information Service (NPIS).

Methods

The number of accesses to TOXBASE, the NPIS online poisons information database, details of consecutive cases uploaded onto TOXBASE and the number and details of telephone enquiries made to the NPIS by health professionals in the UK were collected for the period March 2009 to February 2010.

Results

Over the year of study there were 2901 TOXBASE accesses and 188 telephone enquiries relating to cathinones, the majority relating to mephedrone (TOXBASE 1664, telephone 157), with a month-on-month increase in numbers. In 131 telephone enquiries concerning mephedrone, alone or in combination with alcohol, common clinical features reported included agitation or aggression (n=32, 24%, 95% CI 18% to 33%), tachycardia (n=29, 22%, 95% CI 16% to 30%), confusion or psychosis (n=18, 14%, 95% CI 9% to 21%), chest pain (n=17, 13%, 95% CI 8% to 20%), nausea (n=15, 11%, 95% CI 7% to 18%), palpitations (n=14, 11%, 95% CI 6% to 18%), peripheral vasoconstriction (n=10, 8%, 95% CI 4% to 14%) and headache (n=7, 5%, 95% CI 2% to 11%). Convulsions were reported in four cases (3%, 95% CI 1% to 8%). One exposed person died following cardiac arrest (1%, 95% CI 0% to 4%), although subsequent investigation suggested that mephedrone was not responsible.

Conclusions

Toxicity associated with recreational mephedrone use is increasingly common in the UK. Sympathomimetic adverse effects are common and severe effects are also reported. Structured data collected by the NPIS may be of use in identifying trends in poisoning and in establishing toxidromes for new drugs of abuse.