Clinical Update - Alzheimer's: Evidence from clinical trials show that the behavioural disturbance features of Alzheimer’s disease (AD) can be helped. A subset of patients with dementia can experience significant behavioural disturbance, and it can completely alter their personality.

However, undoubtedly some of those patients have been helped by drug treatments, a leading Irish expert has stated. “The diagnosis of Alzheimer’s disease needs to be clearly established before any drugs are prescribed,” said Prof Cillian Twomey, Consultant Physician in Geriatric Medicine at Cork University Hospital.

“This takes time and cannot be done on a single consultation. When somebody presents with confusion and disorientation, a thorough assessment – examining clinical history – is important, to make sure there is no reversible cause for this behaviour.”

There are two groups of drugs available to treat Alzheimer’s. Medications in day-to-day clinical use include the cholinesterase inhibitors – donepezil (Arecept), galantamine (Reminyl) and rivastigmine (Exelon). Galantamine has the added advantage that it can be administered via a patch, as opposed to tablets.

Memantine (Ebixa) is also available, which modulates glutamate.

Memantine seems to have some benefit in people whose dementia manifests itself in terms of behavioural disturbance.

There is no way of accurately predicting, however, which AD patients may benefit from cholinesterase inhibitors. If somebody has clear-cut AD, the drugs are usually administered for a trial period. After two to three months, a decision on whether to continue treatment is based on general behaviour and ability to cope.

It is the practice of most geriatricians and old-age psychiatrists to continue with treatment if feedback is positive. To a lesser extent, the decision is based on changes in objective scores – the Mini Mental State Examination (MMSE) and Cognitive Disturbance Subscale Scores etc.

It is not uncommon to try the cholinesterase inhibitors and memantine, in conjunction. Memantine can be taken with other Alzheimer’s drugs such as Aricept, Exelon and Reminyl, as it works in a different manner. Memantine has a different source of action to the cholinesterase inhibitors. It modulates glutamate via NMDA receptor antagonism.