Alcohol and paracetamol overdosage
It is assumed, even by many doctors, that drinking alcohol with a paracetamol overdose increases the effect of the overdose and contributes to death. This is the case with many medicines used in overdose, but not with paracetamol. In a normal, healthy adult, alcohol taken with a paracetamol overdose does not increase any injury caused to the liver. In fact, as the two compounds compete for the same metabolic pathways, there may be a protective effect from the alcohol.
However, in alcoholics or habitual drinkers, the changes brought about in the liver by constant alcohol abuse are likely to increase the danger of liver injury from an overdose of paracetamol (1).
'Accidental' paracetamol overdosage
It is extremely rare for anyone to take a fatal overdose of paracetamol by simply 'doubling up' on doses of medicines or by inadvertently mixing different paracetamol products. Such cases have been reported by the press, and sometimes claimed by relatives, but when investigated most have been found to be deliberate overdoses.
Occasionally it has been known for people to take paracetamol for therapeutic purposes but with a reckless disregard for the proper dosage levels, and to thereby take a fatal overdose. Nearly all paracetamol overdoses are taken knowingly, although in some of these cases the expectation was not to die but to go unconscious and then recover, in other words the deliberate attention seeking overdose (2).
Nature of a paracetamol overdose
Many people believe a paracetamol overdose will cause drowsiness or unconsciousness. It doesn't. There are few symptoms apart from perhaps vomiting, for about two days. In a large overdose symptoms will then start to appear including feeling 'ill' and tenderness of the abdomen.
Overdosing and the media
It has been recognised for some time that there is an element of 'copying' in cases of medicines overdose, in that the use of particular medicines for overdosing is popularised by newspaper reports or television programmes, even where the writers have tried to educate readers or viewers.
Evidence shows this copying element is still prevalent, particularly amongst young people. A survey in a Midlands' hospital showed a distinct rise in paracetamol overdose cases in the weeks following a case being featured in a popular television programme. All the patients who overdosed in the period surveyed after the programme admitted to having watched the episode. This has been further confirmed by research on 'before and after' incidence of overdose being featured in a television programme (3). Journalists should bear this in mind when reporting details of suicide at inquests or overdoses by famous people; details given on methods may well be copied.
A fatal overdose of paracetamol, no matter how large, is unlikely to bring about death in under five days, at least some of which are likely to be spent in hospital.
Many overdose deaths are due to a mixture of medicines in which paracetamol is present but, as death is brought about in under 24 hours by medicines other than paracetamol, the paracetamol cannot be a contributing factor in the cause of death.
It may be useful to remember that if death has occurred within 24 hours of an overdose, it was not caused by paracetamol. Similarly if death has occurred outside of hospital, it is unlikely to be due to paracetamol.
Paracetamol and the liver
Because a large paracetamol overdose causes damage to the liver, it is sometimes assumed that a small amount of paracetamol, such as a normal therapeutic dose, will cause small amounts of damage to the liver also. This is not the case. Paracetamol taken at recommended dosages, even long term, does not harm the liver or other organs.
When the liver has been damaged during a non fatal paracetamol overdose, it recovers fully within a matter of weeks or months following the overdose. The liver damage is not permanent, and does not accumulate with subsequent overdoses unless they are taken close together, before the liver has had time to recover (4).
1 Paracetamol, alcohol and the liver, Laurie F Prescott; Br. J Clin Pharmacol (1999); 49; 291-301
2 Deliberate Self-poisoning and Self-injury in Adolescents. A study of Characteristics and Trends in Oxford, 1976-89, Keith Hawton & Joan Fagg, Dept of Psychiatry, Warneford Hosp, Oxford, Br. J Psych (1992); 161; 816-823.
3 Effects of a drug overdose in a television drama on presentations to hospital for self-poisoning: time series and questionnaire study, Hawton K et al.; BMJ (1999); 318; 972-977
4 Paracetamol (Acetaminophen) A Critical Bibliographic Review, Laurie F Prescott; Pub. Taylor & Francis Ltd.; 1996