The concomitant use of meloxicam and methotrexate does not clearly increase the risk of silent kidney and liver damages in patients with rheumatoid arthritis

We investigated whether the concomitant use of meloxicam and methotrexate might induce kidney and liver damages in patients with rheumatoid arthritis (RA). We enrolled 101 RA patients with normal kidney and liver functions taking meloxicam and methotrexate concomitantly for more than 6 months. Blood and urine tests were performed. Estimated glomerular filtration rate (eGFR) and liver stiffness measurement (LSM) were used for evaluating silent kidney and liver damages. Ultrasonography was also performed to exclude structural abnormalities. We adopted 90 mL/min/1.73 mm² and 5.3 kPa as the cutoff for an abnormal eGFR and LSM. The mean age (85 women) was 51.9 years. The mean eGFR was 97.0 mL/min/1.73 m² and the mean LSM was 4.7 kPa. The mean weekly dose of methotrexate was 13.4 mg. The mean weekly dose of methotrexate did not correlate with eGFR or LSM. Neither the cumulative dose of meloxicam or methotrexate nor the mean weekly dose of methotrexate showed the significant odds ratio or relative risk for abnormal eGFR and LSM values. The use of higher-dose MTX, above 15 mg per week, with meloxicam did not significantly increase the risk for abnormal LSM and eGFR (RR = 2.042, p = 0.185; RR = 0.473, p = 0.218). The concomitant use of meloxicam and MTX did not clearly increase the risk of silent kidney or liver damage in RA patients with normal laboratory results taking MTX and meloxicam concurrently for over 6 months.