Discontinuation of oral amitriptyline and nortriptyline due to adverse effects in outpatients with neuropathic pain: a retrospective study

Abstract

Tricyclic antidepressants (TCAs) have side effects but are frequently effective for neuropathic pain. Analgesic effects of amitriptyline (AT) and nortriptyline (NT) are equivalent, however, NT offers higher tolerability than AT. The aim of this study was to investigate the number of outpatients who discontinued with TCAs because of intolerable side effects. We performed a single-center, retrospective study of 87 patients prescribed with AT (AT group) or NT (NT group) from July 2015 to January 2018. Primary outcomes were the ratio of the number of patients who discontinued to that of patients who continued and the type of side effects. TCAs were discontinued by 14/87 patients (7/37 [18％] in the AT group and 7/50 [14％] in the NT group). The side effects were drowsiness (6/37 in the AT group and 2/50 in the NT group), urinary retention (2/50 in the NT group), exacerbation of constipation (1/37 in the AT group and 1/50 in the NT group), and abnormal blood sampling test results (2/50 in the NT group). In conclusion, when prescribing TCAs, clinicians should consider the possibility of side effects that may lead to discontinuation.