In the first six months of 1998 and 1999 similar numbers of patients - around 600 - were treated for paracetamol poisoning in Belfast hospitals.

Withdrawing the means isn't going to have any affect on those people who really want to commit suicide

The Samaritans

But the patients treated in 1999 had taken on average 20 per cent less paracetamol.

In 1998 two patients had to be transferred to a specialist liver unit but both recovered fully.

However, in 1999, three patients required specialist treatment with one needing a liver transplant and one patient dying.

First step

A spokesperson for the Samaritans said the reduction in paracetamol pack size had been a "valuable first step" but what is really needed is help to deal with the underlying problems of isolation and despair.

"Withdrawing the means isn't going to have any affect on those people who really want to commit suicide," she told BBC News Online.

"The change in pack sizes is an admirable initiative but we really need to encourage an environment where people who have suicidal feelings can talk to those around them."

And, the authors of the report, published in the British Medical Journal acknowledged that "the only benefit we noted was a reduction in costs because fewer antidotes were given and there were fewer hospital admissions."