目的 建立高效液相色谱法同时测定人血浆中盐酸纳洛酮及艾司唑仑血药浓度的方法。方法 血浆样品经处理后，采用HPLC测定。色谱柱：Kromasil-C₁₈(4.6 mm×250 mm，5 μm)柱；流动相：甲醇-乙腈-0.02 mol·L^-1磷酸二氢钠（用磷酸调pH至5.2）（39∶26∶35）；流速：1 mL·min^-1；柱温：30 ℃；检测波长：222 nm。采用内标法定量，以地西泮为内标物。结果 盐酸纳洛酮浓度在0.050～0.600 mg·L^-1内线性关系良好，艾司唑仑浓度在0.050～15．001 mg·L^-1内线性关系良好。提取回收率分别为80.22%~84.56%，84.66%~94.84%；方法回收率分别为98.9%~101.2%，99.3%~102.6%。日内、日间精密度分别为3.5%和3.07%，6.66%和6.73%。结论 本法简便、快捷、准确，可以用于临床盐酸纳洛酮治疗艾司唑仑中毒时血药浓度监测及药动学研究。

OBJECTIVE To develop an effective HPLC method for determining the concentrations of naloxone hydrochloride and estazolam in human plasma. METHODS The HPLC method was employed to determine the sample of processed plasma. The column used was Kromasil-C₁₈ column (4.6 mm×250 mm，5 μm). The mobile phase consisted of methanol， acetonitrile and (0.02 mol·L-1) NaH₂PO₄(pH was adjusted with phosphoric acid to 5.2) (39∶26∶35). The flow rate was 1.0 mL·min-1 and the column temperature was 30 ℃.The wavelength was 222 nm. Diazepam was used as internal standard for the quantitation. RESULTS The good linearity of naloxone hydrochloride was obtained in the range of 0.050～0.600 mg·L-1 and estazolam in the range of 0.050-15．001 mg·L-1. The extraction recoveries of naloxone and estazolam were 80.22%-84.56% and 98.9%-101.2% and the method recoveries were 84.66%-94.84% and 99.3%-102.6%. The RSDs of intra-day and inter-day precision were 3.5%，3.07%，6.66% and 6.73%, respectively. CONCLUSION This method is simple， fast and accurate， and is suitable for the determination of its concentration in human plasma when naloxone hydrochloride is administrated to treat patients who are poisoned by estazolam and it is also suitable for pharmacokinetic studies.