The US Government will later this week require by law that pharmaceutical companies study the use of their drugs in children.

BBC Correspondent Gerry Northam reports

At present, the federal agency concerned, the Food and Drug Administration, says that most drugs have not been adequately tested for use by children.

The FDA is offering the multi-billion dollar industry both a stick and a carrot.

The stick is that manufacturers must provide sufficient data to determine the proper use and doses of their products for children of different ages.

The carrot is that those who comply can gain a six-month extension on the monopoly of sales they enjoy under their patents.

It seems inevitable that more drugs than ever before will now be put through clinical trials among American babies and children.

No UK legislation

However, no such legislation applies in the UK, even though the manufacture of pharmaceuticals is one of the great British success stories.

The professional duty of paediatricians is to prescribe appropriate drugs for sick children.

But they often find the manufacturer cannot tell them if a particular drug is appropriate.

Sir David Hull, former President of the Royal College of Paediatrics, has become increasingly worried at how often his colleagues may be prescribing drugs which have not been tested for children.

This may be quite lawful - but Sir David fears that doctors are often unaware of the gamble they are taking.

In the absence of full data from the manufacturer, the obvious rule of thumb for a paediatrician would be to prescribe a child a proportion of the adult dose of a drug, based, say, on the ratio of body weight.

This might work, if a child's body were simply a miniaturised version of an adult's - but this is an over-simplification.

Nine-year-old died

Derek and Debbie Hodge lost their nine-year-old son after their hospital gave him the drug propofol as a sedative - outside the terms for which it's licensed.

As the couple told BBC's File On 4, what began as a severe attack of childhood croup suddenly became a struggle for their son's survival - a struggle they slowly recognised he could not win.

The drug used to sedate their son, is licensed and widely used as an anaesthetic.

It is the use as a longer-term sedative for children needing intensive care that is thought hazardous.

There is a system for reporting serious side effects - adverse drug reactions - but it is widely seen as patchy and unreliable.

Paediatricians are beginning to argue that they and their young patients deserve better.

Pressure for change by the royal college is led by Prof Imti Choonara of Derbyshire Children's Hospital.

He is piloting more thorough recording of drug side effects, and arguing for comprehensive testing of drugs which are prescribed for children.

It is a task that he believes should be shared by the Department of Health and the drug companies.

As a matter of policy, the drug manufacturers support greater testing of medicines for children.

In principle, they would like to see all paediatric drugs tested for relevant age-bands.

Everyone, is seems, agrees. The industry and the medical profession have jointly called the current situation "clearly unsatisfactory" and "unacceptable".

When they explained it to the House of Commons Health Committee, it said in print that it was "astonished to discover" that this was happening.

Little difference

That was two years ago, but little has changed.

Apart from the significant obstacle of cost, Dr Richard Tiner, of the Association of British Pharmaceutical Industries, points to the problem of winning public acceptance for testing children.

Evidence from the US shows how quickly these problems can melt away once there is money to be made.

American paediatricians have established a flourishing network of centres for testing children's drugs, with the active support of parents - and crucially, the drug companies.

The network's director, Professor George Giacoia of Georgetown University, found a positive change in the climate once the government announced that companies supporting paediatric testing could enjoy an extension to their drug's patents, worth many tens of millions of dollars.

Sir David Hull argues that it must, if British children are to have the same rights as adults to safe, effective medicines.