RESUMO
OBJECTIVE: To develop a LC-MS method for simultaneously quantifying four anti-tuberculosis drugs [isoniazid(INH), pyrazinamide(PZA), ethambutol(EMB) and rifampicin(RIF)] in human cerebrospinal fluid and to help guide the clinical medication. METHODS: The drugs in cerebrospinal fluid were extracted by acetonitrile precipitation, and separated on ZORBAX Bonus-RP column(2.1 mm×150 mm, 3.5 μm) with the mobile phase of aqueous solution(containing 0.1% formic acid)-acetonitrile(containing 0.1% formic acid)(80:20) at a flow rate of 0.25 mL•min-1. Multiple reaction monitoring(MRM) mode was performed combined with electrospray ionization source operating in the positive ionization mode. RESULTS: The liner calibration curves of INH, PZA, EMB and RIF were obtained in the concentration range of 20-5 000(r=0.998 6), 120-30 000(r=0.997 7), 20-5 000(r=0.999 4), 60-15 000(r=0.996 2)ng•mL-1, respectively. The intra-and inter-day precision was less than 15% and the absolute recovery was above 75%. This method was successfully applied to analyze the drugs in cerebrospinal fluid from six clinical samples. CONCLUSION: The method is rapid, simple, sensitive and accurate, and proved to be suitable for clinical therapeutic drug monitoring.