Is melatonin (a hormone) suitable for an elderly patient with anemia?

Melatonin for Elderly Patients with Anemia

Melatonin should not be used in elderly patients with anemia as nitrates should be avoided in patients with severe anemia due to potential adverse effects. 1

Contraindications and Concerns

• Nitrates (including melatonin) should be avoided in patients with severe anemia due to increased risk of adverse effects 1
• The American Academy of Sleep Medicine suggests against using melatonin as a treatment for sleep onset or sleep maintenance insomnia in adults (weak recommendation) 1
• Meta-analyses show melatonin's efficacy in improving sleep onset, maintenance, or quality is weakly negative, with very low quality of evidence due to potential publication bias, heterogeneity, and imprecision 1

Evidence in Elderly Populations

• Studies of melatonin (2 mg) have primarily included only older adults (>55 years) with inconsistent results 1
• While some studies show no significant improvement in sleep latency, others found significant reduction in sleep latency specifically in elderly patients (65-80 years) regardless of melatonin deficiency status 1
• A recent study (2022) found that higher dose melatonin (5 mg) significantly increased sleep efficiency during both biological day and night in older adults (>55 years), mainly by increasing Stage 2 non-REM sleep 2

Safety Profile in Elderly

• Melatonin is generally considered to have a favorable safety profile with minimal reported adverse effects compared to placebo across various dosages and durations 1, 3
• However, melatonin has been associated with adverse effects including headaches, somnolence, hypotension, hypertension, gastrointestinal upset at higher doses 1
• A recent publication described impairment in glucose tolerance among healthy women subsequent to acute melatonin administration 1

Alternative Recommendations for Elderly with Sleep Issues

• The American Academy of Sleep Medicine recommends eszopiclone (1-2 mg) as a first-line treatment for elderly patients with insomnia 4
• Zolpidem (5 mg) and zolpidem controlled-release (6.25 mg) are alternative Z-drugs for specific insomnia presentations 4
• Ramelteon (8 mg) may be considered for patients with primarily sleep onset difficulties 4

Dosing Considerations (if melatonin must be used)

• If melatonin is considered despite the anemia contraindication, start with low doses (0.3-1 mg) as these may be more physiological 3, 5
• Doses between 1 mg and 6 mg appear to be effective for improving sleep in older adults, though further studies are needed to find the optimal minimum effective dose 6
• The physiologic melatonin dose (0.3 mg) has been shown to restore sleep efficiency in some studies, acting principally in the middle third of the night 5

Monitoring and Precautions

• If melatonin is used despite contraindications, monitor for worsening anemia symptoms 1
• Higher doses (3.0 mg) can induce hypothermia and cause plasma melatonin to remain elevated into daylight hours 5
• Studies addressing long-term effects of melatonin are scarce, particularly in elderly populations 1