Using Remeron (Mirtazapine) as an Appetite Stimulant in the Elderly
Mirtazapine 7.5-15 mg at bedtime is recommended as a first-line pharmacological option for appetite stimulation in elderly patients, particularly when concurrent depression may be contributing to poor appetite. 1
Clinical Context and Patient Selection
The decision to use mirtazapine for appetite stimulation depends critically on the underlying clinical scenario:
When Mirtazapine IS Appropriate:
Elderly patients with appetite loss AND concurrent depression should receive mirtazapine, as it addresses both conditions simultaneously and is well-tolerated with beneficial side effects including promotion of sleep, appetite, and weight gain. 2
Non-dementia elderly patients with persistent poor appetite may benefit from mirtazapine 7.5-15 mg at bedtime as a first-line agent, particularly when addressing potential underlying mood disorders. 1
When Mirtazapine Should NOT Be Used:
Patients with dementia WITHOUT depression should NOT receive mirtazapine or any appetite stimulants, as the evidence shows no consistent benefit and potentially harmful side effects outweigh uncertain benefits for appetite and body weight. 2
The 2024 Clinical Nutrition guidelines explicitly state that drugs to stimulate appetite should NOT be used in persons with dementia (89% consensus agreement). 2
Dosing and Administration
Start with mirtazapine 7.5 mg at bedtime, which is the recommended initial dose for elderly patients. 2, 1
- The maximum dose is 30 mg at bedtime. 2
- Mirtazapine is potent and well-tolerated, with sedating properties that make bedtime dosing ideal. 2
- A full therapeutic trial requires at least 4-8 weeks to assess efficacy. 2
Expected Outcomes
The evidence for weight gain is limited but suggestive:
- One small retrospective study (n=22) in dementia patients showed mean weight gain of 1.9 kg at three months and 2.1 kg at six months, with approximately 80% experiencing some weight gain. 2
- However, there are NO placebo-controlled trials in elderly patients or those with dementia, making the evidence quality weak. 2
Alternative Options When Mirtazapine Fails
If mirtazapine is ineffective or contraindicated:
Megestrol acetate 400-800 mg/day is an alternative with evidence for improved appetite in approximately 25% of patients and modest weight gain in about 8% of patients. 1, 3
Megestrol acetate increases prealbumin levels in recently hospitalized elderly at doses of 400-800 mg. 4
Critical caveat: Megestrol acetate causes cortisol suppression (common at higher doses and may be persistent), fluid retention, and increased thromboembolic risk. 3, 4
Dexamethasone 2-8 mg/day may be considered for patients with shorter life expectancy due to faster onset of action, but has significant side effects with prolonged use including hyperglycemia, muscle wasting, and immunosuppression. 1, 3
Non-Pharmacological Approaches Should Be Primary
Before initiating any pharmacological intervention:
- Investigate treatable causes of poor appetite including medication review (iron supplements, multiple medications before meals), underlying medical conditions, and depression. 1
- Social interventions such as encouraging shared meals with family or other patients can improve intake. 1
- Dietary modifications including smaller, more frequent meals with favorite foods and energy-dense options maximize nutritional intake. 1
- For dementia patients specifically, focus on feeding assistance, increased time spent by nurses during feeding, emotional support during meals, and specific behavioral and communication strategies. 3
Monitoring and Safety Considerations
- Regular reassessment is essential to evaluate benefit versus harm of pharmacological interventions. 1, 3
- Lower starting doses should be used for elderly patients with close monitoring for side effects, particularly sedation. 3
- After 9 months of treatment, consider dosage reduction to reassess the need for continued medication. 2
- Discontinue over 10-14 days to limit withdrawal symptoms. 2
Critical Clinical Pitfall
The most important caveat is distinguishing between elderly patients with and without dementia. The 2024 guidelines represent the most recent high-quality evidence and explicitly contraindicate appetite stimulants in dementia patients without depression (89% consensus). 2 This represents a shift from older practice patterns and must be respected to avoid potentially harmful interventions with no proven benefit.
If the patient is approaching end of life, focus on comfort and quality of life rather than nutritional goals, and avoid appetite stimulants in this context. 1