Amitryptilne is frequently prescribed for treating chronic pain including tension-type headaches, TMJ disorders and fibromyalgia. It is also used to treat mild insomnia and mild sleep apnea. The drug is classified as a tri-cyclic antidepressant but is frequently used off label in low dose therapy.
The authors concluded that Amytriptiline increasesAHI or apnea /hypopnea index.
This is an interesting finding because sleep disturbances are so closely tied to fibromyalgia and TMJ disorders. The NHLBI, National Heart Lung and Blood Institute published a report "Cardiovascular and Sleep Related Consequences of TMJ disorders. Fibromyalgia is frequently considered in part a disorder of disturbed sleep with UARS, upper airway resistance syndrome frequently associated with the disorder. Worsening of the sleep disordered breating may make the underlying condition worse over time .
This abstract was presented at the AASM meeting in Seattle in 2009.
"EFFECTS OF AMITRIPTYLINE ON AHI Perrott J, Renda F, Fitzgerald H, Botros W Sleep Clinic, Kitchener, ON, Canada
Introduction: Amitriptyline is a tricyclic antidepressant used in the pharmacologic management of depressive illness. Although not a la- beled indication, amitriptyline is widely used as an atypical treatment of insomnia and mild sleep apnea. This is significant due to the fact that the comorbidity between insomnia and sleep related breathing disorders is substantial. Amitriptyline is believed to help mild sleep apnea by im- proving pharyngeal tone. This study will determine the effect of amitrip- tyline on the AHI.
Methods: A sample of 29 patients diagnosed with insomnia that at- tended nPSG without amitriptyline as well as nPSG with amitriptyline were selected. The sample consisted of both males and females between the ages of 18-65. AHI was independently calculated for both diagnostic and therapeutic studies and statistical analysis performed.
Results: The average difference between the diagnostic and therapeutic AHI is an increase of 4.97. For n=29 a one-tailed test was used where Ho: amitriptyline has no effect on AHI and H1: amitriptyline increases AHI. The μ = np = (29)(0.7) = 20.3, σ = 2.46, z = 5-μ/σ = -6.199, α = 0.9998. Therefore 99.9 % of all sample size 29 would lead to rejection of Ho.
Conclusion: Based on the above results it would appear that taking amitriptyline increases the AHI. We acknowledge that the sample size is small and parameters such as increased sleep efficiency were not consid- ered. The practice of prescribing amitriptyline in insomnia patients with mild AHI needs further examination."
