MORE THAN 200 patients are mounting a joint legal action against a pharmaceutical company after taking a drug they claim has either blinded them or left their sight severely impaired.

Lawyers handling the action against Aventis Pharma believe there could be thousands of other potential litigants whom medical studies suggest may face impaired vision after tak­ing the anti-epilepsy drug.

Sabril was brought onto the market in 1989 by Aventis as a way of controlling severe epi­leptic seizures in children and adults. By 1999 more than 80,000 prescriptions a year were being filled for Britain's 440,000 epileptics.

However, recent research sug­gests that up to 40% of epilep­tics who took the drug are likely to lose all their peripheral vision and in the most severe cases their entire sight.

Consultants have restricted use of the drug as they have become more aware of the side-effects but Epilepsy Action, a pressure group, believes thou­sands of patients may still be using it without a clear under­standing of the risks.

Aventis, which says it was unaware of the possibility of such side-effects when it launched the drug in 1989, denies Sabril is the cause of them and is defending the action.

In 2000 the company wrote to users of Sabril warning them the drug had been linked to eye prob­lems. Its website now discloses under SabriFs "undesirable effects" that "visual field defects" are "very common" among people who take it.

One young user of Sabril, Nathan Kerrigan, 14, is now almost blind. He took Sabril for four years from the age of five during which time his parents witnessed a steady deterioration in his eyesight.

His mother Adele said: "I feel terrible because there we; so many times we forced Nathan to take the drug when he didn't want it. We thought would make him better. No my lovely boy has lost his sight."

Adele first noticed something was wrong when Nathan began to bump into objects. He would ask for his glasses to be cleaned because he couldn't see out them. Then last December Nathan walked out in front of bus near his home in Exhall Coventry, and was only narrowly saved by his mother.

Nathan's parents are convinced that his loss of sight due to Sabril and are one of t hundreds of families now suing Aventis. Adele said: "Noboi ever mentioned this could ma him blind. The consultants ji told us it was the best drug control his seizures."

The class action is being coordinated by Tim Roper, a solicitor for Wolferstans of Plymouth. He believes that if this claim is successful the average payout will range from £70,000 to £100,000 with some of the younger victims who require care for life receiving multi milllion-pound settlements.

It is understood Aventis w argue there is no provable link between vision loss and its drug and that it was not aware of the possible side-effect when issued the drug in 1989.