Inconsistent dosing of anti-tuberculosis drugs in Taipei, Taiwan

SETTING: Taipei City, Taiwan. OBJECTIVES: To evaluate prescribing practices for anti-tuberculosis drugs in the treatment of tuberculosis (TB). METHOD: Medical audit of the medical charts of all patients notified and treated for TB in Taiwan in 2003 to determine the treatment regimens prescribed and to compare these with recommended dosages. RESULTS: A total of 24 different anti-tuberculosis regimens were prescribed. Of 1700 patients notified, 1096 (64.5%) had their body weight recorded. Of 506 patients prescribed a three-drug fixed-dose combination (FDC), the dosage was adequate in 374 (73.9%), too low in 100 (19.8%) and too high in 32 (6.3%). Of 75 patients prescribed a two-drug FDC, the dosage was adequate in 57 (76.0%), too low in 15 (20.0%) and too high in 3 (4.0%). Of 481 patients prescribed rifampicin, the dosage was adequate in 302 (62.8%), too low in 152 (31.6%) and too high in 27 (5.6%). Of 451 patients prescribed isoniazid, the dosage was adequate in 396 (87.8%), too low in 29 (6.4%) and too high in 26 (5.8%). CONCLUSION: The prescribing practices for anti-tuberculosis drugs were substandard and need improvement. These findings imply that the National TB Programme needs strengthening.