Controversies in management: Should methionine be added to every paracetamol tablet?

Introduction

Each year in the United Kingdom roughly 2600 million tablets of paracetamol are sold over the counter and 600 million supplied on prescription (Paracetamol Information Centre Study, November 1993). Paracetamol overdose is common in many parts of the world.

In studies in Britain and America paracetamol was the commonest drug used in overdose, being taken in about 48% of overdoses in Oxford1 and 5% in America.2 Clinicians in general, and those working in liver transplant units in particular, are increasingly aware of the problems raised by the liver damage caused by paracetamol, and pressure is growing to find some preventive measure. Adding the antidote methionine3 to paracetamol tablets is attractive, but because most people who take overdoses act impulsively it would have to be added to every formulation to be of maximum value. The critical issue then is whether the vast numbers of responsible users of paracetamol should have no choice but to take it with methionine in order to protect the minority who take overdoses.

Cost of paracetamol poisoning

Overdose of paracetamol causes hepatotoxicity ranging from mild, asymptomatic derangement of liver function to fulminant hepatic failure and death. Official statistics considerably overestimate the number of deaths from paracetamol poisoning.4 Thus in 1990, of 547 deaths attributed to paracetamol in England and Wales, only 150 were substantiated after review.5 The official returns include people who never reach hospital …