Li-jun Zhang, Ya-min Yao, Jian-jun Sun, Jun Chen, Xiao-fang Jia, Fang Shen and Hong-zhou Lu
A quick and high-through LC-MS/MS method has been developed and applied to simultaneously quantify lamivudine (3TC), stavudine(d4T), zidovudine(AZT), efavirenz(EFV), nevirapine(NVP), and Lopinavir/Ritonavir (LPV/RTV) plasma concentrations. A combination of protein precipitation and liquid–liquid extraction was used to extract all compounds. The method showed a good linearity in a concentration range of 20–3200 μ g/L for 3TC, d4T, AZT, 40-6400 μ g/L for EFV and NVP, 62.5-10000 μ g/L for LPV and 12.5-2000 μ g/L for RTV. Mean intra- and inter-day precision were within ±20% at the LLOQ and ±15% at the other QC level. The accuracy were between 85% and 115% for all seven analytes. The whole run is 13 minutes. This method has been successfully used for analyzing 133 samples from 84 HIV-positive patients being treated with the combination therapy in China. To our knowledge, it is the fi rst time to use LC-MS/MS method to simultaneously quantify 3TC, d4T, AZT, EFV, NVP, LPV and RTV in China for investigating the relationship between blood drug concentrations and ef fi cacy and/or toxicity.