From the Guidelines
Amitriptyline can be used for insomnia, though it's not FDA-approved specifically for this purpose, and its efficacy for this indication is not well established 1.
Key Considerations
- It's commonly prescribed off-label at lower doses (10-50 mg) than those used for depression, typically taken 1-2 hours before bedtime.
- The sedating effects come from its antihistamine and anticholinergic properties, which help induce and maintain sleep.
- However, amitriptyline should be used cautiously as it can cause side effects including morning grogginess, dry mouth, constipation, urinary retention, and blurred vision.
- It may be particularly problematic for elderly patients due to these anticholinergic effects and potential for orthostatic hypotension.
Recommendations
- Amitriptyline is generally considered after other sleep interventions have failed, such as sleep hygiene improvements and shorter-acting sleep medications.
- Patients should start at the lowest effective dose (often 10-25 mg) and use it consistently rather than intermittently.
- Abrupt discontinuation should be avoided; instead, the medication should be tapered gradually when stopping treatment.
Guideline-Based Recommendations
- The American College of Physicians recommends cognitive behavioral therapy for insomnia (CBT-I) as the initial treatment for chronic insomnia disorder, with pharmacologic therapy considered if CBT-I is not effective or available 1.
- Pharmacologic therapy options include benzodiazepines, nonbenzodiazepine hypnotics, and off-label use of drugs such as antidepressants, but the comparative safety of these options is not well established.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Amitriptyline for Sleep
- Amitriptyline, a tricyclic antidepressant, is sometimes prescribed off-label for insomnia disorder, specifically to improve sleep maintenance 2.
- A study found that 73.9% of patients with insomnia disorder reported improvement in sleep maintenance after taking low-dose amitriptyline (10-20 mg/day) 2.
- However, another study noted that amitriptyline can induce or increase periodic limb movements during sleep, which may affect sleep quality 3.
Efficacy of Amitriptyline for Insomnia
- A randomized, double-blind, placebo-controlled trial found that low-dose amitriptyline (10-20 mg/day) resulted in a statistically significant reduction in insomnia severity at 6 weeks, but this reduction was not clinically relevant 4.
- In contrast, low-dose mirtazapine (7.5-15 mg/day) provided a statistically significant and clinically relevant reduction in insomnia severity at 6 weeks 4.
- A study protocol outlined a trial to assess the effectiveness of low-dose amitriptyline and mirtazapine for insomnia disorder, highlighting the need for more research in this area 5.
Side Effects and Considerations
- Common side effects of amitriptyline include dry mouth, sedation, and orthostatic hypotension, even at low doses 6.
- Patients taking amitriptyline for insomnia should be monitored for periodic limb movements during sleep, as this can affect sleep quality 3.
- Low starting doses and careful dosage titration may help minimize adverse effects 6.