From the Guidelines
Mirtazapine can be considered as an option to help with Behavioral and Psychological Symptoms of Dementia (BPSD), particularly in patients with agitation, aggression, and sleep disturbances, as well as those with concomitant depressive syndrome. The medication works through multiple mechanisms, including antagonism of alpha-2 adrenergic receptors and serotonin receptors (5-HT2A, 5-HT2C, and 5-HT3), which helps improve mood, reduce anxiety, and promote sleep 1. It's typically started at a low dose of 7.5-15mg at bedtime, which can be gradually increased if needed, though rarely exceeding 30mg in elderly patients. Some key points to consider when using mirtazapine for BPSD include:
- Its potential to stimulate appetite, which may be beneficial in patients with dementia and reduced appetite, as noted in studies where mirtazapine was associated with weight gain in randomized trials on antidepressant therapy 1.
- The importance of regularly reviewing treatment and using the medication as part of a comprehensive approach that includes non-pharmacological interventions for managing BPSD, as emphasized in guidelines that suggest non-pharmacotherapy interventions should take precedence over pharmacotherapy interventions in the treatment of BPSD 1.
- The preference for mirtazapine over antipsychotics for BPSD due to its better safety profile, particularly in elderly patients with dementia where antipsychotics carry black box warnings for increased mortality. Side effects may include sedation, increased appetite, weight gain, and dry mouth. Given the limited but supportive evidence for the use of mirtazapine in this context, particularly from more recent studies 1, it is reasonable to consider its use in clinical practice for managing BPSD, especially when non-pharmacological strategies are insufficient.
From the Research
Mirtazapine and BPSD
- Mirtazapine is a noradrenergic and specific serotonergic antidepressant (NaSSA) that has been studied for its use in various psychiatric disorders, including major depression and anxiety disorders 2.
- While there is limited direct evidence on the use of mirtazapine for Behavioral and Psychological Symptoms of Dementia (BPSD), one study suggests that mirtazapine may reduce the extrapyramidal side effects (EPS) associated with antipsychotic treatment in patients with BPSD 3.
- Mirtazapine's mechanism of action, which involves blockade of alpha2-adrenergic auto- and heteroreceptors and enhancement of serotonergic neurotransmission, may be beneficial in reducing EPS 4, 5.
- In a study on borderline personality disorder, mirtazapine was found to be one of the commonly prescribed medications, with a prescription rate of 18.4% 6.
Potential Benefits and Limitations
- Mirtazapine may be a useful adjunctive treatment for BPSD, particularly in reducing EPS associated with antipsychotic treatment 3.
- However, more research is needed to fully understand the efficacy and safety of mirtazapine in patients with BPSD.
- Mirtazapine's side effect profile, which includes drowsiness, dry mouth, and increased appetite, should be carefully considered when prescribing this medication 4, 2.