Do NOT Use Megestrol Acetate for Appetite Stimulation in Dementia Patients
Drugs to stimulate appetite or weight gain, including megestrol acetate (Megace), should NOT be used in persons with dementia. 1
Why This Recommendation Exists
The evidence against using megestrol acetate in dementia patients is clear and consistent:
Clinical nutrition guidelines explicitly state with 89% consensus agreement that appetite stimulants should not be used in dementia patients due to very limited evidence, inconsistent effects, and potentially harmful side effects that outweigh uncertain benefits for appetite and body weight. 1
Studies testing megestrol acetate in nursing home residents included only 41% with dementia, making the evidence base inadequate for this specific population. 1
In older hospitalized patients with functional decline, 800 mg daily of megestrol acetate actually attenuated beneficial effects of resistance training, resulting in smaller gains or even deterioration in muscle strength and functional performance compared to placebo. 1
Significant Safety Concerns
If megestrol acetate were to be considered despite guidelines (which it should not be in dementia):
Thromboembolic events are a major concern, with documented cases of deep vein thrombosis occurring in geriatric patients, including two cases occurring within 10 days and 4 months of starting therapy. 2, 3
Adrenal suppression is dose-dependent and common: At 400 mg daily, 70% of elderly patients had morning cortisol levels below normal at 20 days, and at 800 mg daily, 78% had suppressed cortisol. 4
Additional side effects include edema, impotence, vaginal spotting, and higher mortality rates compared to placebo in some studies. 2
What Should Be Done Instead
Focus on non-pharmacological interventions that have demonstrated benefit in dementia patients:
Oral care and dental treatment to maintain oral functions, which may prevent pneumonia and other complications. 1
Fortified foods and drinks should be offered to increase energy and protein intake, with Grade B recommendation and 97% consensus agreement. 1
Social interventions such as shared meals can improve intake without medication risks. 2, 5
The Only Exception: Concurrent Depression
Mirtazapine 7.5-30 mg at bedtime may be considered ONLY if the dementia patient has concurrent depression requiring treatment, as it addresses both conditions simultaneously. 2 However, this is for treating depression, not for appetite stimulation alone. 1
One small retrospective study showed mean weight gain of 1.9 kg at 3 months and 2.1 kg at 6 months with mirtazapine in dementia patients. 1, 2
For appetite loss without depression, mirtazapine cannot be recommended. 1
Critical Pitfall to Avoid
Do not extrapolate data from cancer or AIDS cachexia studies to dementia patients – the pathophysiology, prognosis, and risk-benefit calculations are fundamentally different. The studies showing any benefit of megestrol acetate were in mixed populations or non-dementia patients. 1, 6, 7