3.1 Study population
A total of 132 antidepressant users were identified from the B-PROOF
cohort. Of those, 59.8% reported a fall during follow up. InTable 1, the baseline characteristics of fallers and
non-fallers in antidepressant users are shown. Fallers were more often
female, experienced more falls in the 12 months prior to study
enrollment and more frequently used benzodiazepines concomitantly. The
antidepressants most often used were paroxetine (34.6%) and
amitriptyline (23.5%). The range of plasma concentrations were
fluoxetine: <20 µg/L – 366 µg/L (fluoxetine + norfluoxetine),
fluvoxamine: 126-330 µg/L, sertraline: <5 µg/L -91 µg/L,
paroxetine: <5 µg/L -370 µg/L, (es)citalopram: <5
µg/L -174 µg/L, amitriptyline: <22 µg/L -77.7 ug/L
(amitriptyline + nortriptyline), nortriptyline: <22 µg/L -329
µg/L. Median concentrations of the individual antidepressants did not
differ significantly between fallers and non-fallers, both at baseline
and follow-up (Supporting information Table S1). Insupporting information Table S2 present an overview of the
reference values for therapeutic and (potential) toxic concentrations.
Paroxetine, (es)citalopram plasma concentrations were in therapeutic
range, but relatively low. Sertraline and amitriptyline plasma
concentration were below therapeutic range. Nortriptyline plasma
concentrations were higher in fallers compared to non-fallers
(non-significant) and at follow-up above therapeutic range.