What is the lowest dose of trazodone (an antidepressant medication) for insomnia?

Lowest Dose of Trazodone for Sleep

The lowest recommended starting dose of trazodone for insomnia is 25 mg at bedtime, particularly for elderly or debilitated patients, though 50 mg is the most commonly studied dose. 1

Evidence-Based Dosing Recommendations

Starting Doses

• The National Comprehensive Cancer Network (NCCN) recommends 25-100 mg at bedtime for insomnia in palliative care settings, with 25 mg representing the lowest therapeutic starting point. 1
• For elderly or debilitated patients specifically, 25 mg is the recommended starting dose due to increased sensitivity to side effects. 1
• The most commonly studied dose in clinical trials is 50 mg, which the American Academy of Sleep Medicine (AASM) evaluated in their guidelines. 1, 2

Dose-Response Considerations

• Clinical studies from 1999 found that 50-100 mg/day improved sleep disorders, with 100 mg showing particular effectiveness. 3
• In PTSD-related insomnia, 70% of patients found an effective dose range of 50-200 mg nightly. 4
• Lower doses (25 mg) have not been systematically studied in clinical trials, and would likely provide even less benefit than the already modest effects seen at 50 mg. 2

Critical Guideline Warnings

The American Academy of Sleep Medicine recommends AGAINST using trazodone for either sleep onset or sleep maintenance insomnia in adults, giving it a "WEAK" recommendation against use. 2

Why Guidelines Advise Against Trazodone

• At 50 mg, trazodone reduced sleep latency by only 10 minutes and wake after sleep onset by only 8 minutes compared to placebo—improvements that did not reach clinical significance thresholds. 1
• The VA/DoD guidelines also explicitly advise against trazodone for chronic insomnia disorder, noting that its limited efficacy is outweighed by its adverse effect profile. 1, 2
• Clinical trials showed no improvement in subjective sleep quality despite modest objective improvements. 2

Safety Concerns at All Doses

Serious Adverse Effects

• Priapism is a rare but serious side effect that occurred in 12% of patients in one PTSD study—a rate higher than expected. 4
• Daytime drowsiness, dizziness, and psychomotor impairment are particularly concerning for elderly patients. 2

Cognitive and Motor Impairments

• Even at 50 mg, trazodone produced small but significant impairments in short-term memory, verbal learning, equilibrium, and arm muscle endurance. 5
• These cognitive and motor impairments persist despite improvements in sleep maintenance. 5

Practical Clinical Algorithm

When Trazodone May Be Considered (Despite Guidelines)

• Trazodone may be appropriate when insomnia is accompanied by comorbid depression, though low doses (25-50 mg) used for insomnia are not adequate for treating major depression. 1, 2
• It should only be considered as a third-line agent after benzodiazepine receptor agonists and ramelteon have failed. 2

Preferred Treatment Hierarchy

1. First-line: Cognitive Behavioral Therapy for Insomnia (CBT-I) 2
2. Second-line: Short-intermediate acting benzodiazepine receptor agonists (zolpidem, eszopiclone, zaleplon) or ramelteon 2
3. Third-line: Sedating antidepressants like trazodone, only when first and second-line treatments have failed and comorbid depression/anxiety is present 2

If Trazodone Is Used Despite Guidelines

• Start with 25 mg at bedtime for elderly/debilitated patients 1
• Start with 50 mg at bedtime for younger, healthier adults 1, 3
• Take shortly after a meal or light snack to maximize effectiveness 6
• Allow appropriate sleep time (7-8 hours) before activities requiring alertness 1
• Counsel patients directly about priapism risk 4
• Use the lowest effective dose for the shortest possible duration 2
• Regular follow-up is essential to assess effectiveness and side effects 2

Important Caveats

• The FDA-approved dosing for depression starts at 150 mg/day in divided doses, which is far higher than off-label insomnia dosing. 6
• Trazodone's 3-9 hour half-life supports single nighttime dosing rather than divided doses. 7
• Tolerance to sleep-promoting effects does not occur, and REM rebound on discontinuation does not occur. 7
• Gradual dose reduction is recommended when discontinuing to avoid withdrawal effects. 6