FORMER York District Hospital patients were given reassurance today, following claims that they could have been put at risk of life-threatening infections during testing of a drug.

The Sunday Times claimed yesterday that German pharmaceutical company Bayer failed to disclose safety information at the start of a nationwide trial of Ciproxin at six hospitals, including York.

The paper said research conducted by Bayer prior to the testing had shown that it reacted badly in combination with an opiate-based "pre-med" drug, seriously diminishing its ability to kill bacteria.

Mike Porte, medical director at York Health Services NHS Trust, today launched an immediate investigation into the claims.

He later told the Evening Press that 101 patients were given Ciproxin with their consent between March 1993 and August 1995.

But preliminary findings appeared to show that none of the patients were given the combination of drugs which could have increased the risk of post-operative infection.

He said the trust was continuing its inquiries to be absolutely sure that no patients were put at risk.

He spoke of his concern that the ethics committee might have reached its decision on the use of Ciproxin without being given full information.

"Our first priority is the safety and well-being of our patients, and if anyone were to deny our ethics committee information that may have changed its decision, we would regard that as a matter of the utmost seriousness."

He said the trial had appeared to the ethics committee - on the basis of the information available to it at the time - to be "well-constructed" and able to improve the service to patients.

The Sunday Times claimed that Ciproxin, an antibiotic ciprofloxacin, was cleared for a large-scale human trial in surgery in 1993.

But research commissioned by Bayer four years earlier had revealed that it reacted badly with opiate-based, "pre-med" sedatives commonly given to patients before surgery.

Bayer said today the trials were approved by local ethics committees and the competent regulatory authority prior to initiation.

It said patients in a control group given a proven alternative drug to Ciproxin suffered similar infection rates.

A spokeswoman added that the protocol for the trial had been amended during the trial after the research findings had been raised.

Ciproxin was currently used effectively in surgery with other forms of non-opiate, pre-med sedative, she added.