Simultaneous determination of dextromethorphan, dextrorphan and doxylamine in human plasma by HPLC coupled to electrospray ionization tandem mass spectrometry: Application to a pharmacokinetic study

► HPLC-ESI-MS method to quantify dextromethorphan, dextrorphan and doxylamine. ► Method was applied in pharmacokinetic study in human plasma. ► Extraction performed with a simple liquid-liquid extraction. ► High sensitivity, specificity and high throughput.