Should Memantine be discontinued in an Alzheimer's patient with declining MMSE score?

Management of Memantine in an Alzheimer's Patient with Declining MMSE Score

Memantine should be continued despite the decline in MMSE score from 22 to 15, as discontinuation would likely lead to faster cognitive deterioration and functional decline. 1, 2

Rationale for Continuing Memantine

• Rapid cognitive decline (RCD) is common in Alzheimer's disease, affecting approximately 20.1% of mild cases and 43.2% of moderate cases, with a decline of 3 or more points per year on the MMSE considered rapid 1
• The patient's decline of 7 points in approximately 7 months indicates rapid cognitive decline, which is more common in patients with moderate dementia (MMSE 10-19) 1
• Patients with lower baseline MMSE scores (like this patient who now has a score of 15) are more likely to experience rapid decline and may actually benefit more from continued pharmacotherapy 1
• Memantine has been shown to improve cognition, behavior, activities of daily living, and global function in Alzheimer's disease patients, even as monotherapy 2

Understanding the Patient's Decline

• A decline of 3-4 points per year on the MMSE is considered average for Alzheimer's disease patients 1
• This patient's decline of 7 points in approximately 7 months is faster than average, suggesting:
  • Possible progression to moderate-severe disease stage 1
  • Need for more intensive management rather than medication discontinuation 1

Risk Factors for Rapid Cognitive Decline

The patient may have risk factors for rapid decline, which should be assessed:

• MMSE score <20 (patient has 15) - strongest predictor (relative weight 3) 1
• Vascular risk factors (relative weight 2) 1
• Early hallucinations/psychosis (relative weight 2) 1
• Early extrapyramidal symptoms (relative weight 2) 1
• Higher education level (relative weight 1) 1
• Age <70 years at symptom onset (relative weight 1) 1

Recommended Approach

1. Continue memantine at current dose (10 mg morning, 5 mg evening) 1, 2

   • Long-term studies show memantine may inhibit worsening of cognitive function over extended periods 3
   • Discontinuation could lead to accelerated decline 2

2. Consider optimization of treatment:

   • Evaluate for comorbid medical conditions that could be exacerbating cognitive decline 1
   • Consider whether the patient would benefit from increasing to the full dose of memantine (10 mg twice daily) 3
   • Assess for behavioral disturbances that may require additional management 1

3. Increase monitoring frequency:

   • Patients with rapid cognitive decline require more frequent follow-up due to anticipated rapid loss of autonomy and increased caregiver burden 1
   • Reassess cognitive function every 3-6 months rather than the standard 6-month intervals 1

Caution Regarding Medication Changes

• Discontinuing memantine in a patient with moderate Alzheimer's disease (MMSE 15) could result in:

  • Accelerated cognitive decline 2
  • Worsening of behavioral symptoms 2
  • Increased caregiver burden 1
  • Faster progression to severe dementia 3

• While the evidence for memantine's efficacy shows modest effect sizes, it remains one of the few available treatments for moderate-to-severe Alzheimer's disease 2

Common Pitfalls to Avoid

• Misinterpreting decline as medication failure: Cognitive decline despite medication is expected in Alzheimer's disease; medications aim to slow progression, not stop or reverse it 1, 2
• Focusing only on MMSE: Assess function, behavior, and caregiver burden in addition to cognitive measures 1
• Overlooking comorbidities: Rule out delirium, infections, metabolic causes, stroke, depression, and medications with anticholinergic effects that could contribute to rapid decline 1
• Inadequate follow-up: Patients with rapid decline need more frequent monitoring and support 1