Description: Background: Ingestion of pesticides (mainly paraquat) accounted for one-fifth of suicides in South Korea in 2006–10. We investigated the effect on suicide mortality of regulatory action, culminating in a ban on paraquat in South Korea in 2011–12. Methods: We calculated age-standardized method-specific suicide mortality rates among people aged ≥15 in South Korea (1983–2013) using registered death data. Negative binomial regression was used to estimate changes in the rate and number of pesticide suicides in 2013, compared with those expected based on previous trends (2003–11). Results: Pesticide suicide mortality halved from 5.26 to 2.67 per 100 000 population between 2011 and 2013. Compared with the number expected based on previous trends, the regulations were followed by an estimated 847 [95% confidence interval (CI) –1180 to –533] fewer pesticide suicides, a 37% reduction in rates (rate ratio = 0.63, 95% CI 0.55 to 0.73) in 2013. The decline in pesticide suicides after the regulations was seen in all age/sex/geographical groups. The absolute reduction in the number of suicides was greatest among men, the elderly and in rural areas. The reduction in pesticide suicides contributed to 56% of the decline in overall suicides that occurred between 2011 and 2013. There was no impact of the regulations on crop yield. Conclusions: The regulation of paraquat in South Korea in 2011–12 was associated with a reduction in pesticide suicide. Further legislative interventions to prevent the easy availability of highly lethal suicide methods are recommended for reducing the number of suicides worldwide.

Description: Background The absorption, distribution, metabolism and elimination of medicines are partly controlled by transporters and enzymes with diurnal variation in expression. Dose timing may be important for maximizing therapeutic and minimizing adverse effects. However, outcome data for such an effect in humans are sparse, and chronotherapeutics is consequently less practised. We examined a large prospective Sri Lankan cohort of patients with acute poisoning to seek evidence of diurnal variation in the probability of survival. Methods In all, 14 840 patients admitted to hospital after yellow oleander ( Cascabela thevetia ) seed or pesticide [organophosphorus (OP), carbamate, paraquat, glyphosate] self-poisoning were investigated for variation in survival according to time of ingestion. Results We found strong evidence that the outcome of oleander poisoning was associated with time of ingestion ( P 〈 0.001). There was weaker evidence for OP insecticides ( P = 0.041) and no evidence of diurnal variation in the outcome for carbamate, glyphosate and paraquat pesticides. Compared with ingestion in the late morning, and with confounding by age, sex, time of and delay to hospital presentation and year of admission controlled, case fatality of oleander poisoning was over 50% lower following evening ingestion (risk ratio = 0.40, 95% confidence interval 0.26–0.62). Variation in dose across the day was not responsible. Conclusions We have shown for the first time that timing of poison ingestion affects survival in humans. This evidence for chronotoxicity suggests chronotherapeutics should be given greater attention in drug development and clinical practice.