The truth about paracetamol

Paracetamol, one of the most commonly popped pills in the world, is in the news again, with the Government urging drug companies to reduce the number of tablets in the 30 million packets and bottles sold in Britain every year.

In October, liver specialist Sir David Carter called for an outright ban on the drug. It was, he said, the commonest cause of liver failure and responsible for one in 10 of the transplants he carries out. A consultation exercise, launched by the Department of Health, is expected to result in smaller packs of the drug - six or 12 tablets only - being sold in outlets other than pharmacies. There are currently no limits on pack sizes in pharmacies, but the Government is understood to want a maximum of 30 pills.

Paracetamol is an effective pain-killer and one that is recommended for children under 12. It is generally well-tolerated and has few side-effects. The trouble is that it is too easy to kill yourself with it. In normal doses it is metabolised completely and safely by the liver. But if too much is taken at one time, the liver is overwhelmed and some of the drug breaks down to form a toxic compound which destroys the liver cells. The full effect of this may not kick in for a couple of days.

The fatal dose varies from person to person. Some people - alcoholics, for example, or those with existing liver disease - may die after taking only two or three times the recommended amount. Others can take much more and survive.

About 200 people die of paracetamol poisoning each year, and thousands more are treated for it. There is an antidote - a substance called nacetylcysteine - but it only works if the overdose is treated within hours. After that the damage is done.

Paracetamol is particularly cruel on those people, often teenagers, who are making a cry for help rather than a serious suicide bid. After giving everyone a fright they often seem to recover, only to get worse a couple of days later. By the time they get to hospital their livers are shot.

Some survive with permanent damage; some die. Others - if they are lucky - get a transplant.

A "safe" version of paracetamol, in which it is combined with methionine, a compound which protects the liver against paracetamol overdose, is at present causing controversy. One brand, called Pameton, has just been withdrawn from general sale in pharmacies after evidence from its manufacturer, SmithKline Beecham, that methionine might be harmful during pregnancy and for those with a family history of heart disease. Methionine may also interact with drugs used to treat depression, schizophrenia and Parkinson's disease. But another product containing methionine, called Paradote, is still on sale: the manufacturer, Penn Pharmaceuticals, says it has no information about adverse side-effects. Paradote can be bought at any chemists. At pounds l.67 for 24, it is more expensive than unbranded paracetamol, which costs pounds l.35 for 100 tablets.

Alternatively, for adult use, there is aspirin or the aspirin derivative, ibuprofen. The drawback with aspirin is that it can cause stomach problems and allergic side-effects like skin rash and wheezing. Ibuprofen is kinder to the stomach, but still has more side-effects than paracetamol. Both aspirin and ibuprofen should be avoided if you are pregnant or breast- feeding, have asthma or blood, liver or kidney trouble.

Children under 12 should not be given aspirin because of the risk of Reye's syndrome - a potentially fatal illness which affects the liver and brain. Ibuprofen is generally unsuitable for children, too. Smaller- dose preparations of paracetamol in tablet or liquid form are available for children and are usually more palatable.

Aspirin, ibuprofen and paracetamol all work by reducing the effect of prostaglandins - the hormones which cause pain.

Paracetamol works on prostaglandin receptors in the brain, however, while the others work at the site of the pain. The analgesic effects of all three are similar, but aspirin and ibuprofen have the added bonus of reducing inflammation. Aspirin also protects against cardiovascular disease and possibly some cancers.

Whichever drug you use, take it before the pain becomes bad. Stoically waiting until severe pain sets in makes it far more difficult for the drug to work. And always take the recommended dose. Taking more does not increase the pain-killing effect of common analgesics - but it does increase their risksn