Stereo-specific LC and LC-MS bioassays of antidepressants and psychotics

Stereochemistry in drug action is gaining importance because the enantiomers often differ in their biological activity and pharmacokinetic profiles. The use of racemic drugs may contribute to adverse effects owing to the presence of either inactive or toxic enantiomers. Most of the drugs currently used to treat psychiatric disorders, including depression, contain one or more chiral centers and are mostly sold as racemates. Single-enantiomer drugs provide greater selectivity for their biological targets, improved therapeutic indices and better pharmacokinetics compared with racemates. Therefore it is of great importance to monitor body fluid/tissue levels of drugs used to treat depression and psychiatric disorders. The present manuscript gives an overview of liquid chromatographic and mass spectrometric techniques reported during 2000-2013 for enantiomeric separation of various classes of antidepressants, viz. selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, noradrenergic and specific serotonergic antidepressants, norepinephrine reuptake inhibitors, norepinephrine-dopamine reuptake inhibitors, nonamphetamine central nervous system stimulants, serotonin and dopamine inhibitors and γ-aminobutyric acid receptor agonists in biological matrices. Techniques used for extraction, separation and quantification are discussed.