Effects of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the United Kingdom: before and after study

Objective To evaluate the effects on suicidal behaviour of legislation limi ting the size of packs of paracetamol and salicylates sold over the counter . Setting UK population, with detailed monitoring of data from five liver uni ts and seven general hospitals, between September 1996 and September 1999. Subjects People who died by suicidal or accidental overdose with paracetamo l or salicylates, or who died of undetermined causes; patients admitted to liver units with hepatic paracetamol poisoning; patients presenting to gene ral hospitals with self poisoning after taking paracetamol or salicylates. Main outcome measures Mortality from paracetamol or salicylate overdose; nu mbers of patients referred to liver units or listed for liver transplant; n umbers of transplantations; numbers of overdoses and tablets taken; blood c oncentrations of the drugs; prothrombin times; sales to pharmacies and othe r outlets of paracetamol and salicylates. Results Numbers of tablets per pack of paracetamol and salicylates decrease d markedly in the year after the change in legislation on 16 September 1998 . The annual number of deaths from paracetamol poisoning decreased by 21% ( 95% confidence interval 5% to 34%) and the number from salicylates decrease d by 48% (11% to 70%). Liver transplant rates after paracetamol poisoning d ecreased by 66% (55% to 74%). The rate of non-fatal self poisoning with par acetamol in any form decreased by 11% (5% to 16%), mainly because of a 15% (8% to 21%) reduction in overdoses of paracetarnol in non-compound form. Th e average number of tablets taken in paracetarnol overdoses decreased by 7% (0% to 12%), and the proportion involving > 32 tablets decreased by 17% (4 % to 28%). The average number of tablets taken in salicylate overdoses did not decrease, but 34% fewer (2% to 56%) salicylate overdoses involved > 32 tablets. After the legislation mean blood concentrations of salicylates aft er overdose decreased, as did prothrombin times; mean blood concentrations of paracetamol did not change. Conclusion Legislation restricting pack sizes of paracetamol and salicylate s in the United Kingdom has had substantial beneficial effects on mortality and morbidity associated with self poisoning using these drugs.