High-performance liquid chromatographic method to screen and quantitate seven selective serotonin reuptake inhibitors in human serum

A high-performance liquid chromatographic screening method (HPLC) is descri bed for the determination of seven selective serotonin reuptake inhibitors (SSRIs) (fluvoxamine, milnacipran, paroxetine, sertraline, fluoxetine, cita lopram, venlafaxine) and for three pharmacologically active N-demethylated metabolites (desmethylcitalopram, didesmethylcitalopram and norfluoxetine). A tricyclic antidepressant, clomipramine, was used as an internal standard . The method consists of liquid extraction of serum after alcalinisation at pH 9.50, followed by chromatography on a Beckman C-18 reversed-phase colum n. Compounds were detected at 200.4 nm. The standard curves were linear ove r a working range of 50-1000 ng/ml for fluvoxamine, 15-1000 ng/ml for fluox etine, 25-500 ng/nd for norfluoxetine, 50-500 ng/ml for sertraline, 20-500 ng/ml for paroxetine, 25-550 ng/ml for citalopram, 25-750 ng/ml for desmeth ylcitalopram, 25-800 ng/ml for didesmethylcitalopram, 25-650 ng/ml for miln acipran, and 25-500 ng/ml for venlafaxine. The quantitation limits of the m ethod were 15 ng/ml for fluoxetine, 20 ng/ml for paroxetine, 25 ng/ml for v enlafaxine, norfluoxetine and citalopram, and its metabolites, 40 ng/ml for sertraline and 50 ng/ml for fluvoxamine. No interferences were noted with this sensitive and specific method which can be used for therapeutic drug m onitoring. (C) 2001 Elsevier Science B.V. All rights reserved.