Selling painkillers in smaller pack sizes has slashed rates of suicides involving overdoses, research suggests.
Researchers say pack sizes should be reduced further
Legislation, introduced in 1998, cut pack sizes and the number of tablets retailers and pharmacies could sell.
Oxford University researchers looked at suicides involving painkillers in the UK between 1993 and 2003.
Almost 25% fewer people took fatal aspirin and paracetamol overdoses in the three years after 1998 than before, they told the British Medical Journal.
The Oxford team also found that numbers of tablets taken in non-fatal overdoses of aspirin and paracetamol fell significantly after the legislation.
As a result, admissions to liver units for paracetamol poisoning and numbers of related liver transplants also dropped heavily - down by nearly a third (30%) in the four years after the laws came into force.
Researchers analysed rates of suicides and non-fatal overdoses from paracetamol, salicylates (aspirin) and ibuprofen across the UK between 1993 and 2003.
PAINKILLER SALE RESTRICTIONS
Before September 1998:
Other retail outlets: max of 24 tablets
After September 1998:
Pharmacies: max of 32 tablets
Other retail outlets: max of 16 tablets
While overdosing from paracetamol and salicylates - both covered by the new laws - decreased, patterns of overdosing from ibuprofen, which was not targeted in the legislation, remained roughly the same.
The researchers argue that although smaller pack sizes do not prevent someone from buying multiple packs from various retailers, many of those who overdose do so impulsively - using tablets to hand in the home.
They say their research provides a strong argument for reducing pack sizes still further.
Marjorie Wallace, chief executive of the mental health charity SANE, said: "We are particularly pleased that one of the government's initiatives to reduce the suicide rate has apparently been successful.
"We have become increasingly concerned at the numbers of people who self-harm, and their increased risk of suicide.
"However, we must not forget that overdosing is only one of the ways in which people sadly take their own lives: the most common method of suicide for young men is hanging."
A spokesperson for mental health charity Mind said: "The research certainly seems to indicate that suicides can be prevented by selling painkillers in smaller packs.
"Anything that guards against as tragic and as painful a death as those caused by paracetamol overdose should be welcomed."
Mike Owen, from the Proprietary Association of Great Britain, also welcomed the findings.
He said the industry was keen to ensure over-the-counter products were packaged and sold in a safe and responsible way.
Nick Henderson, of the International Ibuprofen Foundation, said research had shown that suicide attempts with ibuprofen were unlikely to be successful unless other drugs were involved.