Find 'may cut painkiller damage'

Too much paracetamol can damage the liver

Scientists have made a discovery which they hope could reduce liver damage and prevent deaths caused by paracetamol overdoses.

They found overdose patients who suffer the greatest liver damage have higher levels of a protein known as cyclophilin A in their urine.

The University of Edinburgh team says treatments to block the harmful effects of the protein may aid such patients.

About 200 people die each year in the UK following a paracetamol overdose.

Last year 20 overdose patients underwent a liver transplant.

The researchers said that measuring levels of the protein could also enable doctors to determine much sooner which patients are most at risk of liver failure.

PARACETAMOL Widely used painkiller For adults, recommended safe dose 500mg -1,000mg (one or two tablets) every four to six hours Should not take more than 4,000mg (usually eight tablets) in 24-hour period In higher doses can cause potentially fatal liver damage Leading cause of acute liver failure in Western world In rare cases a normal dose can be enough to cause liver damage

This would mean that high-risk patients could be placed on a liver transplant waiting list sooner, providing more time to find a suitable donor organ.

Lead researcher Dr James Dear said: "Around 30% of patients who have developed significant liver injury following a paracetamol overdose die.

"If we can find a way to block the protein cyclophilin A, we would hope to limit further damage to the liver.

"Alternatively, measuring levels of the protein could indicate straight away which patients will need a liver transplant.

"Waiting a number of days means that valuable time is lost in trying to find a suitable match. Even gaining an extra day or two could save a life."

Dr Varuna Aluvihare, a consultant hepatologist at King's College Hospital, London, said a test to assess which patients needed a liver transplant would potentially be of great use.

However, he warned that in many cases patients who had taken an overdose of paracetamol did not present to specialist services until it was too late to offer effective treatment.

He said that at the specialist unit at King's more than half of all cases of acute liver failure were due to paracetamol overdose.

Part of the problem was that symptoms took three to four days to appear, but by that stage the damage had already been done.

The findings will be presented at a meeting of the British Pharmacological Society.