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Guide Health: Antipsychotic drugs and dementia

Drugs may ease the anxiety and aggression, but they introduce other risks

Guide Health: Antipsychotic drugs and dementia

Dementia is a progressive irreversible decline in both cognitive and functional abilities. About seven per cent of Canadians have a diagnosis. Unfortunately, there is no cure.

It is thought that tangles of proteins known as tau particles and plaques of misshaped amyloid beta proteins impair the brain’s ability to function. Nerve messages are not able to travel as once they did. As well, levels of the neurochemical acetylcholine decline, and the brain actually shrinks.

Keep in mind that once a nerve cell is damaged or dies, it can neither be repaired nor regenerate.

The symptoms of dementia may begin as a subtle memory loss, but can develop into confusion, inability to concentrate, personality changes and even the inability to perform everyday tasks. One group of symptoms of dementia includes psychological manifestations such as delusions, aggression and agitation. In fact, these occur in 60 to 90 per cent of people with dementia.

The thinking is that because these are psychological symptoms, antipsychotic drugs may help (for example risperidone, olanzapine, quetiapine) and they certainly will have a “sedating” or “calming” effect for these psychological symptoms.

Dosing antipsychotic drugs in dementia is at a much lower level than for psychosis diagnoses. Ideally, the dose and effectiveness need to be revisited on a regular basis, because as dementia progresses, psychological symptoms diminish and these drugs may no longer be needed. Tapering off these drugs is usually recommended rather than just stopping them suddenly. 

There are numerous negative aspects to using antipsychotic drugs in dementia. They are generally used off-label in that there is no indication for their use, and thus no dose recommendations. Many long-term care facilities consider the use of antipsychotic drugs to be chemical restraints, similar to physical restraints. And, research only shows modest improvements.

As well, antipsychotic drugs increase cardiovascular and cerebrovascular risks, that is heart attacks, arrhythmias, stroke, which may not be ideal for older individuals already at risk for these adverse events.

Side effects include constipation, urinary retention, and dizziness or lightheadedness, none of which are ideal for older individuals. Psychological symptoms may be curtailed, but the individual falls and breaks a bone!

The drugs that are available to treat dementia generally work by leaving more neurochemicals in the brain to improve functioning, but only work early in the diagnosis with mild to moderate dementia when there are still sufficient nerve cells that can be impacted.

The newest drug for dementia is the once-a-month infusion, aducanumab, which shrinks the amyloid plaques. However, there still is no cure for dementia, only treatments that slow the progression.

Antipsychotic drugs perhaps should be reserved for cases where the safety of the individual with dementia and/or their caregivers is at risk. Otherwise, keeping healthy is the best defense against dementia, that is keep good control of conditions like diabetes or hypertension, wear the appropriate head gear to prevent head injury, eat healthy and be active.

About the author

Contributor

Marie Berry is a lawyer/pharmacist interested in health and education.

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