The European Parliament has approved a law intended to boost the production of children's medicines.
It costs companies more to make drugs for children than for adults
The law obliges firms producing a drug for adults in the EU to test whether it can also be used for children.
It also gives firms an new incentive to produce children's drugs, by adding six months to the patent protection period.
At present most of the drugs prescribed to children have not been tested for paediatric use, forcing doctors to guess the right dose.
The law was passed a day after UK scientists unveiled a study suggesting that two-thirds of children treated in hospital are given drugs that have not undergone appropriate tests.
At present drug firms focus on making medicine for adults, because the market and the financial returns are larger.
Testing drugs on children is also more complicated and costly, because different age groups require different doses.
The regulation on medicinal products for paediatric use creates a new European paediatric committee to assess companies' plans for testing child medicines, and to absolve companies from carrying out the tests if the drug clearly has no application for children.
- creates a fund to finance research into the possible adaptation of existing drugs, which are not covered by patents, for use by children
- sets up a network of researchers and research centres designed to prevent duplication of research and tests on children
Similar legislation encouraging the production of medicines for children already exists in the US.
The French Conservative MEP who shepherded the law through the parliament, Francoise Grossetete, described it as a big advance for science and health.
"This is about saving children's lives," she said.
"Our children will benefit from medicines that are tailored for their use and reliable."
Extra patent period
British Labour MEP Linda McAvan also described the vote as a breakthrough.
"Experts say that very young children can't express how much pain they are in, don't like injections and are at risk of choking on tablets.
"Children also have different absorption rates from adults. For all these reasons it is clear that we need to make medicines tailored for children."
The parliament voted to extend the patent period for children's medicines by six months, as proposed by the European Commission.
Some EU member states, including Hungary and Poland, had argued for a shorter extension, in order to support their generic drug manufacturers.
They will have a chance to vote on the law when it goes to the EU Council for approval.
However, parliamentary sources said it was unlikely they would be able to organise a blocking minority, and that the regulation would probably have a smooth passage into law.