Halving the pack sizes of paracetamol has seen a significant drop in overdose deaths from the drug, according to a new BMJ study.

In September 1998 the Labour government passed new laws to half the 36-tab pack size of the drug, after a high number of deaths from paracetamol poisoning and liver unit activity.

The study, published in the British Medical Journal this week and the first long-term report on this legislation’s effect, found that the passing of the law was followed by a significant reduction in deaths due to paracetamol overdose between 1998 and 2009.

Specifically, they found there were 765 fewer deaths after the legislation was introduced in 1998 than would have been predicted based on trends dating back to 1993, which equated to an average of 17 fewer deaths every three months after 1998.

It also found some indication of fewer registrations for transplantation at liver units during the 11 years after the legislation.

But the Oxford University authors warn that the continuing toll of deaths suggests that further preventive measures should be sought, as the number of people taking overdoses has not declined.

Prof Keith Hawton, lead researcher from the University of Oxford Centre for Suicide Research, told the BBC: “While some of this effect could have been due to improved hospital management of paracetamol overdoses, we believe that this has in large part been due to the introduction of the legislation.

“We are extremely pleased that this measure has had such benefits, but think that more needs to be done to reduce the toll of deaths from this cause.”