In draft guidance, the National Institute for Health and Clinical Excellence (NICE) said that patients should be denied drugs when the symptoms first appeared, but allowed them once the disease had advanced.

The point at which they would become eligible was the same as when patients became unable to care for themselves, said the Alzheimer’s Society, declaring the decision unethical and lacking clinical sense. “It is a very poor judgment,” said Clive Ballard, the director of research. “It puts doctors in an almost impossible position. Their patients have got to get worse before they can prescribe drugs designed to stop them getting worse.”

But Andrew Dillon, the chief executive of NICE, said drugs showed a clinically significant benefit only when symptoms had worsened to “moderate”.

The new guidance is less restrictive than an earlier version that suggested that three drugs — donezepil (Aricept), galantamine (Reminyl), and rivastigmine (Exelon) — should not be prescribed because they were not cost-effective.

NICE received thousands of letters in protest when that guidance was published.

The new guidance, published today, is its response.

Neil Hunt, of the Action on Alzheimer’s Drugs alliance, representing more than 30 charitable and professional organisations, said: “We are relieved that NICE has withdrawn its plan to place a blanket ban on the only drug treatments. However, the new draft guidance still raises serious ethical and practical concerns.”

NICE studied evidence that the three drugs were effective, and found that they were. But it employs an analysis that seeks to quantify the benefit in terms of what it costs to buy an extra year of good quality life.

NICE looked for ways of identifying sufferers who might justify the annual cost of £800 to £1,000 a patient. Cognitive tests indicated that the only patients showing a clear benefit were those with moderate Alzheimer’s.

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• Litvinenko murder suspect's peace offer
• Low rollers seize chance to scoop £5m on the nose
• I wish I were Chancellor now, says Ken Clarke