A decision by an NHS drugs body to reject greater access to certain drugs has been criticised by North Down MP Lady Hermon.
Lady Hermon said the drug is effective
Campaigners say the decision will harm tens of thousands of patients suffering from Alzheimer's Disease.
Lady Hermon, whose husband former RUC chief constable Sir Jack Hermon, is a sufferer, said she had no doubt about the effectiveness of one of the drugs.
"It undoubtedly helped stabilise Jack's condition," she said.
"I have absolutely no doubt as a carer.
"It is a very cruel illness indeed. He was diagnosed four years ago when our boys were only ten and 12, so they were very young.
"The medication was introduced at that stage."
Campaigners had argued patients in the early stages of Alzheimer's should have access to the £2.50-per-day drugs.
The National Institute for Health and Clinical Excellence said donepezil, rivastigmine and galantamine could be used to treat moderate stage disease.
However, the NICE added that studies showed the drugs "did not make enough of a difference."