Dual role for drugs
Computer graphic of a vertical (coronal) slice through the brain of an Alzheimer's patient (left) compared with a normal brain (right)
Controversy surrounds the use of so-called sedative neuroleptic, or antipsychotic, drugs in the treatment of dementia. These powerful drugs are helpful in the treatment of schizophrenia, but are also prescribed to more than 100,000 people with Alzheimer’s disease in the UK alone as a treatment for behavioural symptoms such as aggression.
Clive Ballard of the Wolfson Centre for Age-Related Diseases and the MRC Centre for Neurodegeneration Research, together with Robert Howard, has carried out an analysis of the use of atypical neuroleptic drugs in treating psychiatric symptoms in Alzheimer’s disease patients. Their studies included a six-month double-blind placebo controlled trial to examine the treatment of agitation in people with Alzheimer’s disease. The trial showed that neuroleptic drugs significantly and substantially increase the rate of cognitive decline in these patients. A subsequent meta-analysis of several other intervention studies using neuroleptic drugs has corroborated this finding and emphasised additional serious concerns related to increased rates of stroke and death.
There are some 25 million people with Alzheimer’s disease worldwide, a number that is set to grow as people live longer. Alzheimer’s is a devastating illness, causing progressive degeneration of the brain. This leads to memory loss, confusion and a loss of intellectual skills, coupled with great distress to sufferers and those around them. Mood swings and behavioural problems associated with this form of dementia are common. Neuropsychiatric symptoms, such as aggression and bipolar disorder, are seen in 90 per cent of patients at some time during their illness.
The King’s research, published in the journal Nature Reviews Neuroscience and British Medical Journal (2005), has demonstrated that, rather than improving the wellbeing of patients, neuroleptic drugs actually accelerate the development of Alzheimer’s disease in the brain. The researchers suggest that safer treatments based on sychological and other approaches are urgently needed, and have recently published a further paper demonstrating the value of this approach in a cluster randomized trial in the British Medical Journal (2006). Nevertheless, the team did find that neuroleptic drugs are effective in the short-term treatment of psychiatric and behavioural symptoms in people with Alzheimer’s disease. In particular, the most positive results were seen in clinical trials with the drug risperidone for controlling aggression. However, this study and independent research found that neuroleptic drugs in general come with an increased risk of stroke and increased mortality. Moreover, researchers have found no evidence that these drugs work in the long term.
The interpretation of meta-analysis for clinical practice is based to a degree upon subjective opinion, but the team concludes that using atypical neuroleptic drugs can be effective as a short-term treatment for patients with severely distressing symptoms that cannot be easily contained and that pose a risk to the patient and others.
Source: Health Schools Annual Review 2005/06