The highest doses tested for each of these compounds in randomized clinical trials for this population were: risperidone 2 mg/d, olanzapine 10 mg/d, and aripiprazole 15 mg/d. A wide variety of maximum doses of quetiapine were studied in clinical trials, with a top dose of 200 mg being most common. It is worth noting that doses higher than these have been used for other indications.15-22
Quetiapine. One of the most commonly prescribed antipsychotics for the treatment of BPSD in individuals with memory disorders is quetiapine. The reasons for this preference include a low risk of extrapyramidal adverse effects, flexibility of dosing, ability to use lower dosages, and evidence of the lower risk of mortality when compared with other second-generation agents.5,15 If an antipsychotic is indicated, quetiapine should be considered as a first-line antipsychotic therapy. Quetiapine has well-established effects on mood, anxiety, and sleep, all of which can be disrupted in dementia and can act as drivers for agitation.5,15 Starting quetiapine may mitigate the need for separate agents to treat insomnia, loss of appetite, or anxiety, although it is not FDA-indicated for these comorbid conditions. Quetiapine is also less likely to exacerbate motor symptoms compared with other SGAs but has the potential to increase the risk of falls, and orthostasis, and carries a considerable anticholinergic burden.5,15
Risperidone has been shown to provide modest improvements in some people exhibiting symptoms of aggression, agitation, and psychosis.5,15 There is no evidence that risperidone is any more effective than other SGAs, but it has been tested on more geriatric patients than other SGAs. The fact that it is also available in an orally disintegrating tablet makes it a practical treatment in certain populations of patients, such as those who have difficulty swallowing. Risperidone carries the highest extrapyramidal symptom burden among the SGAs due to its potent D2 receptor binding. 5,15
Aripiprazole. There have been several studies of aripiprazole for the treatment of psychosis and agitation in Alzheimer’s dementia.15 This medication showed modest effect and was generally well tolerated. Aripiprazole appears to have less associated weight gain, which may be pertinent for some patients. It also appears to be less sedating than many of the other SGAs. However, some patients may experience activation or insomnia with this agent, particularly with doses <15 mg/d. This activating effect may be beneficial for treating comorbid depressive symptoms, although lower doses could theoretically worsen psychosis due to the activating effects.
Aripiprazole has also been studied in Parkinson’s disease. While some patients had favorable responses with improvement in psychosis and behavioral disturbances, this medication was also associated with worsening of motor symptoms. Certain individuals also experienced a worsening of their psychosis.23 For this reason, it is unlikely to be a useful agent for patients displaying evidence of parkinsonism, Parkinson’s dementia, or dementia with Lewy bodies.
Olanzapine. Several studies have shown that low-dose olanzapine has been modestly effective in decreasing agitation and aggression in patients suffering from Alzheimer’s and vascular dementias.24 The medication is also available in an orally disintegrating form, which may be beneficial when treating individuals whose swallowing abilities are compromised. Olanzapine also has been associated with significant weight gain and metabolic syndrome.24
Continued to: Ziprasidone