Is there evidence for the use of gabapentin in patients with sundowning (sundown syndrome) in dementia?

Gabapentin for Sundowning in Dementia

Gabapentin should be considered as a third-line agent for sundowning in dementia patients when non-pharmacological interventions and first-line medications have failed. 1

Non-Pharmacological Approaches (First-Line)

Non-pharmacological interventions should always be implemented first for managing sundowning in dementia:

• Light therapy: Increase exposure to bright light (3,000-5,000 lux) for 2 hours in the morning to decrease daytime napping and increase nighttime sleep 2
• Environmental modifications:
  • Reduce nighttime light and noise
  • Maintain comfortable room temperature
  • Create a structured bedtime routine 2
• Activity scheduling:
  • Increase daytime physical and social activities
  • Reduce time spent in bed during the day
  • Maintain consistent sleep-wake schedules 2
• Exposure to zeitgebers (environmental time cues):
  • Ensure 30+ minutes of daily sunlight exposure
  • Engage in regular social activities 2

Pharmacological Management Algorithm

First-Line Medications

1. Cholinesterase inhibitors (donepezil, rivastigmine, galantamine)

   • May improve behavioral symptoms including sundowning 2
   • Case reports show improvement in sundowning with donepezil in dementia with Lewy bodies 3

2. SSRIs (citalopram, sertraline)

   • Preferred for behavioral symptoms with minimal anticholinergic effects 2

Second-Line Medications

1. Melatonin

   • Consider for circadian rhythm regulation, though evidence is inconsistent 2
   • May be effective in patients with known melatonin deficiency 2

2. Trazodone

   • Can be used for agitation in dementia 1
   • Starting dose: 25 mg/day; maximum: 200-400 mg/day 1

Third-Line Medications

1. Gabapentin
   • Can be considered when first and second-line treatments fail 1, 4
   • Limited evidence from case reports shows effectiveness for nocturnal agitation 5
   • May help control agitation and aggression in dementia patients 4

Evidence for Gabapentin in Sundowning

The evidence for gabapentin in sundowning is limited:

• A systematic review found no randomized controlled trials evaluating gabapentin for agitation in dementia 4
• Case series and reports (87 patients) suggest possible benefits for behavioral symptoms 4
• One case report demonstrated convincing improvement in nocturnal agitation with gabapentin 400mg at bedtime in a 77-year-old woman with vascular dementia 5

Important Considerations and Cautions

• Start low, go slow: Begin with low doses and titrate slowly while monitoring for side effects
• Monitor for adverse effects: Sedation, dizziness, and ataxia are common side effects
• Regular reassessment: Use quantitative measures like the Neuropsychiatric Inventory Questionnaire (NPI-Q) to evaluate treatment effectiveness 1
• Avoid medications that worsen cognition: Opioids, anticholinergics, and sedatives should be used with extreme caution 1
• Time-limited trials: Consider gabapentin as a short-term intervention with regular attempts to reduce or discontinue

Pitfalls to Avoid

• Undertreatment of underlying pain: Pain can manifest as agitation in dementia patients
• Overreliance on medications: Always maintain non-pharmacological approaches alongside medication
• Inadequate monitoring: Regularly assess for both efficacy and side effects
• Failure to rule out medical causes: Delirium, pain, infection, and other medical conditions can mimic or exacerbate sundowning

In conclusion, while gabapentin may be helpful in selected cases of sundowning in dementia, it should be reserved for patients who have not responded to non-pharmacological approaches and first-line medications, with careful monitoring for efficacy and adverse effects.