What medication adjustments can be made to alleviate nighttime agitation related to sundowning in a patient with dementia?

Management of Nighttime Agitation Related to Sundowning in Dementia

For a 94-year-old patient with dementia experiencing nighttime agitation related to sundowning, mirtazapine is the most appropriate medication adjustment to make, as it promotes sleep, has sedating properties, and is already prescribed at a low dose that can be optimized.

Understanding Sundowning in Dementia

• Sundowning syndrome is characterized by the emergence or worsening of neuropsychiatric symptoms such as agitation, confusion, anxiety, and aggressiveness in late afternoon, evening, or at night in persons with dementia 1
• It is highly prevalent among individuals with dementia and is associated with impaired circadian rhythmicity, environmental factors, and cognitive impairment 1
• Neurophysiologically, it appears to be mediated by degeneration of the suprachiasmatic nucleus of the hypothalamus and decreased melatonin production 1

Current Medication Assessment

The patient is currently taking:

• Mirtazapine 7.5 mg (quarter tablet) in the evening
• Melatonin 3 mg in the evening
• Several other medications that don't specifically target sleep/agitation (amlodipine, aspirin, atorvastatin, benzonatate, vitamin D3, diclofenac gel, furosemide, omeprazole, ondansetron)

Pharmacological Approaches

First-Line Recommendation:

• Optimize mirtazapine dosage: Increase from current quarter tablet (7.5 mg) to full tablet (30 mg) at bedtime 2
  • Mirtazapine is potent, well-tolerated, promotes sleep, appetite, and weight gain
  • The therapeutic dose for elderly patients with dementia and agitation is up to 30 mg at bedtime
  • The patient is already on a very low dose that can be titrated upward

Alternative/Additional Options:

• Continue melatonin therapy: The patient is already taking 3 mg; consider timing optimization 2

  • While evidence for melatonin in dementia is inconsistent, it may help regulate circadian rhythm with minimal side effects
  • Studies show a trend toward improvement at higher doses (up to 10 mg) 2

• Consider low-dose antipsychotic only if agitation is severe and other approaches fail 2, 3

  • Low-dose risperidone may be effective for controlling agitation with relatively low risk of extrapyramidal symptoms 3
  • Quetiapine or olanzapine are alternatives for severe agitation 2
  • CAUTION: Use antipsychotics only when benefits clearly outweigh risks due to increased mortality risk in elderly patients with dementia

Non-Pharmacological Approaches (Should Be Implemented First)

• Light therapy: Increase daytime light exposure and avoid bright light in the evening 2

  • Bright light exposure (3,000-5,000 lux) for 2 hours in the morning has been found to decrease daytime napping and increase nighttime sleep 2
  • Light therapy helps consolidate nighttime sleep, decrease agitated behavior, and improve circadian rhythms 2

• Structured daily activities and sleep hygiene 2

  • Encourage physical and social activities during daytime
  • Establish consistent bedtime routines
  • Reduce nighttime noise and light
  • Minimize daytime napping

• Environmental modifications 2

  • Reduce evening stimulation
  • Provide familiar surroundings
  • Address incontinence issues promptly

Special Considerations

• Rule out other causes of nighttime agitation 4

  • Restless Legs Syndrome (RLS) may manifest as nighttime agitation in dementia
  • Consider checking iron status (transferrin saturation) as iron deficiency can worsen RLS symptoms
  • Review medications that might worsen RLS (antihistamines, serotonin reuptake inhibitors)

• Avoid medications that may worsen cognition or increase fall risk 2

  • Benzodiazepines should be avoided in older patients with cognitive impairment 2
  • Traditional neuroleptics have limited efficacy and high rates of adverse effects 3

Implementation Plan

1. Start with optimizing non-pharmacological approaches (light therapy, daily structure)
2. Increase mirtazapine from quarter tablet to half tablet (15 mg) for one week, then to full tablet (30 mg) if needed and tolerated 2
3. Ensure melatonin is given 1-2 hours before desired bedtime
4. Monitor for side effects and effectiveness
5. If insufficient response after 2-4 weeks of optimized mirtazapine, consider consultation with geriatric psychiatry for possible addition of low-dose antipsychotic 2