original article
The effect of folic acid supplementation in different ways on liver toxicity of methotrexate
2007 Volume 19 Issue 2 Pages 83-88
Details
2007 Volume 19 Issue 2 Pages 83-88
Objective. To ascertain the method and the effect of folic acid (FA) supplement for liver damage due to methotrexate (MTX).
Patients and Methods. Elevation of transaminase levels occurred in 119 (26.4%) of 450 patients with rheumatoid arthritis treated by MTX. Among 119 patients, 30 (25.2%) had transient elevation of tranaminases without using FA, 84 (70.6%) were supplemented with FA, and 5 (4.2%) withdrew or reduced MTX. Of 84 patients with FA, we analyzed 59 patients for which we had sufficient retrospective data from medical charts. When the transaminase levels normalized or decreased by more than half after FA supplementation, we defined this as a good response to liver toxicity.
Results. For 3 months, 19 patients were supplemented with FA daily (daily group), 18 took FA with MTX simultaneously (simultaneous group), and the remaining 22 patients were supplemented with FA 24 to 48 hours after taking MTX (subsequent group). The average doses of FA per week were 55.3 mg in the daily group, 13.6 mg in the simultaneous group and 6.1 mg in the subsequent group. The ratios of FA to MTX doses (F/M) were 8.0 in the daily group, 1.9 in the simultaneous group and 0.8 in the subsequent group. After 3 months, the rate of good responses to liver toxicity in the daily group (94.7%) were higher than those of the simultaneous group (77.8%) and in the subsequent group (77.3%), however, there was no statistical difference among the 3 groups.
After 6 months, 11 in the daily group, 12 in the simultaneous group and 17 in the subsequent group had continued FA supplement. The average dose of FA and F/M were almost the same as those after 3 months. The rate of good response to liver toxicity in the daily group (100%) was significantly higher than the combined rate (65.5%) of the simultaneous group (58.3%) and the subsequent group (70.6%) (p＝0.038).
Conclusion. There was no significant difference of the good response rate to liver toxicity among the three groups for 3 months. In contrast, the daily FA supplement provided for 6 months significantly improved liver toxicity compared to the other 2 groups.
