Adverse drug events associated with nortriptyline compared with paroxetine and alternative medications in an older adult population: a retrospective cohort study in Southern California

Abstract

ObjectiveInvestigate risk for falls, fractures and syncope in older adult patients treated with nortriptyline compared with paroxetine and alternative medications.DesignRetrospective cohort study.SettingThe electronic medical record and prescription drug database of a large integrated healthcare system in Southern California.ParticipantsAmbulatory patients, age ≥65 years diagnosed with depression, anxiety disorder or peripheral neuropathy, dispensed one or more of ten study medications between 1 January 2008 and 31 December 2018.Main outcome measuresHR for falls, fractures and syncope with exposure to study medications adjusted for patient demographic variables and comorbidities.ResultsAmong 195 207 subjects, 19 305 falls, 15 088 fractures and 11 313 episodes of syncope were observed during the study period. Compared with the reference medication, nortriptyline, the adjusted HRs (aHRs) for falls were statistically significantly greater for: paroxetine (aHR 1.48, 95% CI 1.39 to 1.57), amitriptyline (1.20, 95% CI 1.08 to 1.33), venlafaxine (1.44, 95% CI 1.34 to 1.56), duloxetine (1.25, 95% CI 1.12 to 1.40), fluoxetine (1.51, 95% CI 1.44 to 1.59), sertraline (1.53, 95% CI 1.44 to 1.62), citalopram (1.61, 95% CI 1.52 to 1.71) and escitalopram (1.37, 95% CI 1.21 to 1.54), but not gabapentin (0.95, 95% CI 0.89 to 1.02). For fractures, compared with nortriptyline, aHRs were significantly greater for: paroxetine, venlafaxine, duloxetine, fluoxetine, sertraline, citalopram, escitalopram and gabapentin, with aHRs ranging from 1.30 for gabapentin to 1.82 for escitalopram; risk was statistically similar for amitriptyline. For syncope, the aHRs were significantly greater for: paroxetine, venlafaxine, fluoxetine, sertraline and citalopram, with aHRs ranging from 1.19 for fluoxetine and paroxetine up to 1.30 for citalopram and sertraline; risk was similar for amitriptyline, duloxetine, escitalopram and gabapentin.ConclusionsCompared with therapeutic alternatives, nortriptyline was found to represent a lower risk for falls, fractures and syncope, versus comparator medications, except for a few instances that had equivalent risk. The risk for these adverse events from paroxetine was comparable to the alternative medications.