Abstract:

Objective Based on therapeutic drug monitoring (TDM), the adjustment results of plasma drug concentration of the anti-tubercular drugs isoniazid (INH), rifampicin (RFP) and pyrazinamide (PZA) were analyzed.Methods Using the information management system of Xi’an Chest Hospital to collect and analyze blood drug concentration monitoring data of 132 cases that had applied plasma drug concentration monitoring for two or more times and adjusted the oral dosages to meet the need of clinical treatment from November 2016 to November 2017. Among them, there were 50 and 19 INH-treated cases, 47 and 9 RFP-treated cases, and 35 and 11 PZA-treated cases who performed TDM for two or more times and dose adjustment, respectively. The drug dose adjustment of each treatment group was analyzed.Results The plasma concentration adjustment rates of the INH, RFP, and PZA groups were 38.0% (19/50), 19.1% (9/47), and 31.4% (11/35), respectively. The dose adjustment success rate of plasma drug concentration in the INH group was only 31.6% (6/19), and that of the RFP and PZA groups were 7/9 and 81.8% (9/11), respectively. The result of precise probability test indicated that there was a significant difference in the adjustment success rate of plasma drug concentrations among the three drug groups. The adjustment success rate of INH plasma drug concentration was significantly lower than that of RFP and PZA (Fisher’s exact probability method, P=0.013).Conclusion The blood concentrations of the three first-line anti-tubercular drugs were all not nicely within the clinical therapeutic range after once dose adjustment, and the plasma concentration of INH was even less controllable than that of RFP and PZA. This analysis suggests that the drug regimens adjustment based on TDM for one time can not be perfectly implemented, and for specific individuals and drugs it is also necessary to practise further TDM monitoring and dosage adjustment.

Key words: Tuberculosis, pulmonary, Antibiotics, antitubercular, Drug monitoring, Dose-response relationship, drug, Outcome assessment (health care)