Treatment of Depression: Are Psychotropic Drugs Overdosed in Women and in the Elderly? Dosages of Psychotropic Drugs by Sex and Age in Clinical Routine

Abstract

Background:Psychotropic drugs show higher concentration-dose ratios in women and in the elderly. Furthermore, women partially exhibit more adverse drug reactions than men. Lower dosages in most psychotropic drugs may be recommended in women and in the elderly. This study describes prescribed dosages of psychotropic drugs in depressive patients across sexes and age groups in clinical routine. Method:In 32’082 inpatients with depressive disorders (data acquired by the European drug safety program AMSP), the influence of sex and age on prescribed dosages are analysed for the 10 most commonly prescribed drugs in our dataset (descending in the frequency of prescription: mirtazapine, venlafaxine, lorazepam, quetiapine, citalopram, escitalopram, olanzapine, duloxetine, zopiclone and sertraline) and additionally zolpidem. Confounding variables for sex differences, such as severity of depression and age distribution are examined. Dose decline in patients over 65 years is calculated. The observed sex and age differences in prescriptions are compared to differences in pharmacokinetic literature.ResultsAmong patients over 65, a statistically significant decrease in dosages for increasing age (between 0.65% and 2.83% every year of age) was observed, except for zopiclone. On the other hand, only slight or no influence of sex in prescribed dosages was found.ConclusionAge definitely influences physicians’ decisions in most drugs, but to a lower extent than pharmacokinetic data suggests. Although lower dosages of psychotropic drugs are appropriate for females according to pharmacokinetic data, they are usually prescribed the same dosage as males. Thus, various psychotropic drugs may be overdosed in women.