tricyclics for insomnia

Last edited 05/2020

Low doses (sub-therapeutic for depression) of sedating tricyclics, particularly amitriptyline, have been used for decades to treat insomnia

  • particularly common practice in primary care in the UK, where amitriptyline 10 or 25 mg is also used for long periods in many patients with chronic illness, particularly those with pain syndromes

  • at 10 or 25mg dose, amitriptyline is probably acting mostly as a histamine H1 receptor antagonist although a degree of 5-HT2 and cholinergic muscarinic antagonism may
    also contribute

  • no controlled studies of hypnotic efficacy of low-dose amitriptyline in insomnia, and tricyclics are more likely to be lethal than licensed hypnotics in overdose

  • controlled trials demonstrate an effect of doxepin in insomnia at sub-antidepressant dose (25 mg) for four weeks, with rebound insomnia

A review stated (2):

  • " data analysis with two medications at particular doses (most studies included extremely low doxepin), we assert that tricyclic antidepressants (TCA)s can be an effective pharmacological treatment for insomnia. TCAs were found to improve sleep outcome measures, with the notable exception of an 82% increase in somnolence. Overall TCAs have very problematic and dangerous side effects, while TCAs were not found to increase the dropout rate compared with the placebo.."