Therapeutic Drug Monitoring of Antidepressants in Haemodialysis Patients

Abstract

The co-morbidity of depressive disorder and chronic kidney failure is remarkably common. However, knowledge about the influence of haemodialysis on the serum concentration of antidepressants is sparse. In this study we examined the influence of haemodialysis on the serum concentrations of the antidepressants amitriptyline (and its active metabolite nortriptyline) and mirtazapine. The authors retrospectively evaluated therapeutic drug monitoring (TDM)-analyses obtained in eight different regional medical dialysis centres before and after haemodialysis and compared serum concentrations of amitriptyline and mirtazapine using t-tests. Mean serum concentrations of the sum of amitriptyline + nortriptyline (before: 75.52 ng/mL; after: 59.35 ng/mL; p < 0.001) and mirtazapine (before: 53.45 ng/mL; after: 38.31 ng/mL; p < 0.036) decreased significantly with haemodialysis. Haemodialysis patients received rather low doses of amitriptyline (mean 36.5 mg; SD 17.6; range 10-75 mg) and mirtazapine (mean 24.7 mg; SD 9.1; range 15-45 mg). For haemodialysis patients with depression an adequate antidepressant drug dosage must be administered. TDM is necessary in order to optimize antidepressant therapy in patients with chronic kidney disease.