Can melatonin (MLT) 5 mg be started in adults?

Melatonin 5 mg Use in Adults

Melatonin 5 mg is not recommended as a treatment for general insomnia in adults, though it may be considered for specific circadian rhythm disorders such as Delayed Sleep-Wake Phase Disorder (DSWPD). 1, 2

General Recommendations for Insomnia

• The American Academy of Sleep Medicine (AASM) explicitly suggests that clinicians not use melatonin as a treatment for sleep onset or maintenance insomnia in adults 1
• This recommendation is based on trials of 2 mg doses of melatonin, which showed insufficient evidence of clinical benefit 1
• Cognitive behavioral therapy for insomnia (CBT-I) is the preferred first-line approach for both sleep onset and maintenance insomnia 2

Specific Uses of Melatonin 5 mg in Adults

• For adults with Delayed Sleep-Wake Phase Disorder (DSWPD), 5 mg melatonin timed between 19:00-21:00 for 28 days has shown some benefit 1
• In studies of adults with DSWPD, 5 mg melatonin decreased sleep latency by 37-43 minutes and increased total sleep time by 41-56 minutes 1
• The AASM suggests melatonin for DSWPD with a "WEAK FOR" recommendation, indicating benefits likely outweigh harms but many patients might choose not to use this treatment 1

Dosing Considerations

• Clinical studies have used various doses ranging from 0.5 mg to 10 mg in adults 3, 4
• For general adult use, effective doses typically range from 1-5 mg 3
• For older adults (>55 years), doses between 1-6 mg appear effective for improving sleep 4, 5
• A recent study found that 5 mg significantly increased sleep efficiency during both biological day and night in older adults, while 0.3 mg only improved daytime sleep 5

Safety Considerations

• Short-term side effects of melatonin at doses of 5 mg or less are generally mild 3, 6
• Common side effects include daytime sleepiness 6
• The benefits/harms ratio remains uncertain, as long-term safety data (>6 months) are lacking 6
• Potential concerns include:
  • Interactions with other medications (largely unexplored) 6
  • Effects on reproductive function (theoretical concern based on animal studies) 6

Clinical Decision Algorithm

1. For general insomnia in adults:

   • First consider CBT-I or FDA-approved medications (eszopiclone, zolpidem, temazepam) 1, 2
   • Melatonin 5 mg is not recommended 1

2. For adults with DSWPD:

   • Consider melatonin 5 mg taken between 19:00-21:00 for 4 weeks 1
   • Monitor for improvement in sleep onset and total sleep time 1

3. For older adults (>55 years) with sleep difficulties:

   • Consider melatonin 1-6 mg, with 5 mg showing efficacy in recent research 4, 5
   • Take 30 minutes before desired bedtime 5

Common Pitfalls

• Using melatonin as first-line therapy for general insomnia when evidence doesn't support this practice 1, 2
• Failing to distinguish between general insomnia and circadian rhythm disorders, where melatonin may have different efficacy 1
• Not considering timing of administration, which is critical for effectiveness in circadian disorders 1
• Assuming that higher doses are always more effective - some studies show efficacy at lower doses with fewer side effects 4, 7