The drug, zonisamide, marketed under the trade name Zonegran, was already available on prescription in Scotland for adults at risk of seizures from epilepsy or other conditions.
However, the decision by the Scottish Medicines Consortium gives the green light for the treatment to be offered to children aged six and over. It comes after the European Commission agreed to a similar step.
Professor Martin Brodie, director of the epilepsy unit at the Western Infirmary in Glasgow, said: "Uncontrolled epilepsy can affect all aspects of children and their family's lives and so new, effective and well-tolerated medications are always needed." Prof Brodie said he had first-hand experience of the drug's effectiveness in reducing seizures - the most common type of epilepsy - in adults, and added: "I look forward to seeing this opportunity extended to children and adolescents."
The so-called gold standard of scientific trials -double blind randomised testing - showed 50% of young patients benefited from zonisamide, compared with 31% who did better on a placebo. The drug was approved for use in adults in the EU in 2005.
The study last year found so-called adverse events related to the drug's use were minimal and those taking zonisamide had no more such events than patients offered a placebo.
Epilepsy affects around 54,000 people in Scotland and around 63,400 people aged 18 years and under in the UK.