Can You Give 5mg Melatonin After Discontinuing 150mg Doxepin?
Yes, you can give 5mg of melatonin after she previously took 150mg of doxepin, but this represents a significant change in therapeutic approach that requires understanding the context and expected outcomes.
Critical Context: Doxepin Dosing Discrepancy
The dose of 150mg doxepin mentioned is substantially higher than evidence-based dosing for insomnia. The American Academy of Sleep Medicine recommends doxepin at 3-6mg doses for sleep maintenance insomnia, not 150mg 1. At 150mg, doxepin was likely being used for depression or other psychiatric indications rather than purely for sleep 1.
Melatonin Dosing Recommendations
Standard Adult Dosing
- The American Academy of Sleep Medicine does NOT recommend melatonin (at 2mg doses) for chronic insomnia treatment 1, 2
- However, for REM sleep behavior disorder, melatonin starting at 3mg at bedtime, titrated up to 15mg in 3mg increments is recommended 1
- Research suggests 5mg melatonin significantly increases sleep efficiency during both biological day and night in older adults, primarily by increasing Stage 2 NREM sleep 3
Evidence-Based Dosing by Context
- Adults with insomnia: 1-5mg is commonly used in clinical practice, though guideline support is weak 4
- Elderly patients: 1-6mg range, with 5mg showing efficacy in selected populations 4, 5
- Psychiatric patients: 5mg melatonin showed fewer adverse effects than trazodone or doxepin, though slightly less effective for sleep quality improvement 6
Clinical Decision Algorithm
If She Was Taking 150mg Doxepin for Depression/Psychiatric Indication:
- 5mg melatonin will NOT replace the antidepressant effects of high-dose doxepin 1
- Melatonin addresses only sleep, not mood or psychiatric symptoms 6
- You must address the underlying psychiatric condition with appropriate alternative treatment 6
If She Was Taking 150mg Doxepin Solely for Sleep (Off-Label High Dose):
- 5mg melatonin is a reasonable alternative, though expectations should be adjusted 3, 4
- Melatonin has better tolerability with fewer adverse effects than doxepin, including lower rates of morning grogginess (5% vs 13%) and no anticholinergic effects 6
- Sleep efficacy may be reduced compared to high-dose doxepin, particularly for sleep maintenance 6
Important Caveats and Pitfalls
Melatonin Limitations
- Melatonin is most effective for sleep onset, not sleep maintenance 1, 2
- If her primary issue was staying asleep (which doxepin 3-6mg addresses well), melatonin may be insufficient 1
- Bioavailability varies significantly across over-the-counter formulations; recommend products with U.S. Pharmacopeia Verification Mark 1
Withdrawal Considerations
- Abrupt discontinuation of 150mg doxepin may cause withdrawal symptoms including rebound insomnia, anxiety, and anticholinergic rebound 1
- Taper doxepin gradually rather than switching abruptly to melatonin
- Monitor for psychiatric symptom emergence if doxepin was treating underlying mood disorder 6
Dosing Optimization
- Start melatonin 30-60 minutes before desired bedtime 1
- If 5mg is insufficient, can titrate up to 15mg in 3mg increments based on REM sleep behavior disorder protocols 1
- Immediate-release formulation is preferred over prolonged-release for most insomnia presentations 1
Alternative Evidence-Based Options
If melatonin proves inadequate, consider:
- Low-dose doxepin (3-6mg) specifically for sleep maintenance insomnia 1, 2
- Eszopiclone 2-3mg for both sleep onset and maintenance 1, 2
- Zolpidem 10mg for sleep onset and maintenance 1, 2
- Cognitive behavioral therapy for insomnia (CBT-I) as first-line non-pharmacological treatment 2
Monitoring Plan
- Assess response within 2-4 weeks of melatonin initiation 2
- Monitor for inadequate sleep onset (may need dose increase to 10-15mg) 1, 3
- Watch for persistent sleep maintenance problems (may require switching to different agent) 1, 2
- Evaluate for psychiatric symptom emergence if doxepin was treating comorbid conditions 6