The Chinese patent medicine Tongfengding capsule for gout in adults: a systematic review of safety and effectiveness

ABSTRACT

Abstract Background Gout is a common inflammatory arthritis caused by increased serum uric acid levels. Untreated or insufficiently treated gout can lead to deposition of monosodium urate crystals in joints, cartilage, and kidneys. Although Tongfengding capsules, a Chinese patent medicine, have long been used to treat gout, their effects and safety have not been reviewed systematically. This study evaluated its efficacy and safety for gout in adults. Methods Randomized controlled trials involving Tongfengding capsule for gout in adults were searched from PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CBM, CNKI, and VIP databases, and analyzed using the Cochrane Handbook criteria. The primary outcome measures were the total effective rate. The secondary outcome measures including the blood uric acid (BUA), 24-h urinary total protein (24-h UTP), blood urea nitrogen (BUN), interleukin (IL)-6, IL-8, tumor necrosis factor-alpha (TNF-α) and adverse effects. The risk of bias was evaluated in all included studies. RevMan ver. 5.3.5 and GRADE profiler was used for data analysis and assessing the quality of evidence, respectively. Results Six studies (n = 607 Chinese participants) were included. Tongfengding capsules plus conventional treatment significantly increased the total effective rate (RR 1.21, 95% CI 1.11-1.33), while reducing the BUA (MD − 66.05 μmol/L, 95% CI − 81.26 to − 50.84), 24-h UTP (MD − 0.83 g/24 h, 95% CI − 0.96 to − 0.70), BUN (MD − 0.90 mmol/L, 95% CI − 1.60 to − 0.20), IL-6 (MD − 6.99 ng/L, 95% CI − 13.22 to − 0.75), IL-8 (MD − 12.17 ng/L, 95% CI − 18.07 to − 6.27), TNF-α (MD − 8.50 ng/L, 95% CI − 15.50 to − 1.51), and adverse effects (RR 0.21, 95% CI 0.04-0.95). Conclusion Tongfengding capsules plus conventional treatment is safe and beneficial for adults with gout compared with conventional treatment.