Background: Sleep is one of the most essential processes required to maintain a healthy human life, and patients experiencing psychiatric illness often experience an inability to sleep. The aim of this study is to test the hypothesis that antidepressant compounds with strong binding affinities for the serotonin 5-HT2C receptor, histamine H1 receptors, or norepinephrine transporter (NET) will be associated with the highest odds of somnolence.
Methods: Post-marketing cases of patient adverse drug reactions were obtained from the United States Food and Drug Administration Adverse Events Reporting System (FAERS) during the reporting window of January 2004 to September 2019. Disproportionality analyses of antidepressants reporting somnolence were calculated using the case/non-case method. The reporting odds-ratios (ROR) and corresponding 95% confidence interval (95% CI) were computed and all computations and graphing conducted in R.
Results: There were a total of 69,196 reported cases of somnolence out of a total of 7,366,864 cases reported from January 2004 to September 2019. Among the 30 antidepressants assessed, amoxapine (n = 16) reporting odds-ratio (ROR) = 7.1 (95% confidence interval [CI] [4.3-11.7]), atomoxetine (n = 1,079) ROR = 6.6 (95% CI [6.2-7.1]), a compound generally approved for attention deficit hyperactivity disorder (ADHD), and maprotiline (n = 18) ROR = 6.3 (95% CI, 3.9-10.1) were the top three compounds ranked with the highest reporting odds of somnolence. In contrast, vortioxetine (n = 52) ROR = 1.3 (95% CI [1.0-1.8]), milnacipran (n = 58) ROR = 2.1 (95% CI [1.7-2.8]), and bupropion (n = 1,048) ROR = 2.2 (95% CI [2.1-2.4]) are least significantly associated with somnolence. Moreover, levomilnacipran (n = 1) ROR = 0.4 (95% CI [0.1-2.9]) was not associated with somnolence.
Conclusion: Among the thirty tested antidepressants, consistent with the original hypothesis, amoxepine has strongest 5-HT2C receptor binding affinity and has the highest reporting odds of somnolence. Atomoxetine, ranked second in reporting odds of somnolence overall, binds to the NET with with the strongest binding affinity among the thirty compounds. Mirtazapine, a tetracyclic antidepressant, was ranked 11th in reporting odds of somnolence and had the strongest H1 receptor binding affinity. This study provides an informative ranking of somnolence among thirty antidepressant compounds with an already wide array of clinical indications as well as provides insight into potential drug repurposing in psychopharmacology.
Keywords: CYP2C19 poor metabolizers; CYP2D6 poor metabolizers; Clinical pharmacology; Depression and anxiety; Glymphatic system; Insomnia; Pharmacogenomics; Psychopharmacology; Sleep; Somnolence.
©2020 Eugene.