Memantine Dose Titration and Safety Monitoring
Start with 5 mg once daily and increase by 5 mg increments weekly until reaching the target dose of 20 mg/day (10 mg twice daily), which takes 4 weeks to complete. 1
Dose Titration Schedule
The FDA-approved titration follows this specific weekly progression 1:
- Week 1: 5 mg once daily (2.5 mL)
- Week 2: 10 mg/day (5 mg twice daily = 2.5 mL twice daily)
- Week 3: 15 mg/day (5 mg morning + 10 mg evening as separate doses)
- Week 4 onward: 20 mg/day (10 mg twice daily = 5 mL twice daily) - this is the therapeutic target dose
The minimum interval between dose increases must be one week - do not accelerate this schedule 1. Memantine can be taken with or without food 1.
Monitoring for Dizziness and Falls
Dizziness and falls are recognized adverse effects that warrant discontinuation if they become intolerable 2. The Canadian Consensus Conference specifically lists "confusion, dizziness, falls" as intolerable side effects requiring memantine discontinuation 2.
However, the safety profile is generally favorable. In pooled clinical trial data involving 2,311 patients, dizziness occurred in only 6.3% on memantine versus 5.7% on placebo, and falls occurred in 6.8% versus 7.1% on placebo 3. These rates are essentially equivalent to placebo, suggesting memantine itself does not substantially increase fall risk beyond baseline dementia-related risk.
Specific Monitoring Actions:
- Assess baseline fall risk before starting treatment (gait stability, orthostatic vital signs, concurrent medications)
- Monitor for dizziness at each weekly dose escalation
- Evaluate for new falls or near-falls at follow-up visits
- Check for orthostatic hypotension if dizziness develops
- Review all concurrent medications that may contribute to falls (sedatives, antihypertensives, anticholinergics)
Fall Prevention Strategies
While on memantine, implement these practical measures:
- Environmental modifications: Remove tripping hazards, improve lighting, install grab bars in bathroom
- Assistive devices: Ensure proper use of cane/walker if already prescribed
- Footwear: Non-slip shoes with good support
- Supervision: Increase caregiver awareness during titration period
- Avoid polypharmacy: Minimize other CNS-active medications when possible
Important Caveats
If doses are missed for several days, do not resume at the previous dose - you must restart at a lower dose and retitrate 1. This is critical for safety.
Renal dose adjustment required: If creatinine clearance is 5-29 mL/min (severe renal impairment), the target dose is only 5 mg twice daily (10 mg/day total), not 20 mg/day 1, 4. Notably, 60% of patients requiring renal dose adjustment are incorrectly prescribed full doses in clinical practice 4.
Hepatic impairment: Use with caution in severe hepatic impairment, though specific dose adjustments are not defined 1.
The overall discontinuation rate due to adverse events is low (8.9% for memantine versus 9.8% for placebo) 3, and long-term treatment up to 2 years demonstrates continued safety and tolerability 5, 3.