A NEW drug has been introduced in Scotland to battle hospital superbug Clostridium difficile (C Diff) but it will only be available to patients who have the infection for a second time.

Fidaxomicin, the first antibiotic for the potentially fatal disease since the 1950s, is now available for restricted use on the NHS under guidance from the Scottish Medicines Consortium (SMC).

The drug is better at preventing recurrence of the infection than other treatments, but the SMC claimed there was not enough evidence to suggest it made financial sense for it to be used on those contracting the bug for the first time.

Health campaigners said the move fell short of what was needed and called for fidaxomicin to be made more widely available.

Margaret Watt, chairwoman of the Scotland Patients Association, said: "I thought the drug was coming on to the market to help people. I didn't think we were going to ration it to people contracting the infection for the second time.

"That's actually a wee bit of discrimination. When you're sick, you're sick. It doesn't matter whether it's the first time or the second time.

"I hear what they're saying about the funding of it, but I'm sure there are other places we can make savings.

"The quicker we can heal these people, the quicker they'll be out of their hospital beds."

In clinical trials, fidaxomicin worked as well as the current gold standard drug, vancomycin, in clearing the infection, but more than halved the rate of recurrence in patients, which is viewed as the biggest problem in the treatment of C Diff. Up to 25% of patients treated for the infection using current drugs end up contracting it again.

However, a spokesman for SMC – which advises NHS Scotland on new treatments – said the manufacturer of the drug, known commercially as Dificlir, did not present "a sufficiently robust economic analysis to gain acceptance for first-line use in adults with severe C Diff".

The spokesman added that patients contracting the disease for the second time required more time in hospital and were more likely to develop it a further time.

Despite the restricted use guidelines, Professor Robert Masterton, director of the Institute of Healthcare Associated Infection at the University of the West of Scotland, claimed the move was a breakthrough.

He said: "This is excellent news for patients. There has been much improvement in the management of C Diff in Scotland in recent years, but it is still a major cause of hospital-acquired infection. The approval of fidaxomicin represents a notable milestone in combating the still significant impact and spread of this disease."

C Diff is caused by a bacterial infection of the internal lining of the colon and affects more than 2000 people a year in Scotland. In 2010, it contributed to 270 deaths. The cost to the NHS in Scotland of treating the disease is estimated to be in excess of £2 million a year.

It is a significant problem in nursing homes and hospitals and mostly affects patients with a weakened immune system.

Scotland's worst outbreak of the infection was at the Vale of Leven Hospital where 55 patients developed the bug and 18 died between December 2007 and June 2008. An inquiry into the outbreak is ongoing.

Mr Masterton said: "Although C Diff can affect anyone at any age, it is the over-65s who are most vulnerable to infection. With the increasing elderly population the threat of further C Diff outbreaks cannot be ignored.

"It poses a risky in hospitals, nursing homes and other long-term care facilities. It is important we employ all possible measures to contain this disease. Widespread and early access to the new antibiotic fidaxomicin will make a real difference."