Rheumatoid arthritis (RA) is the most common chronic inflammatory disease with unknown causes and unknown cures in Western medicine. This double-blinded study aimed to investigate the efficacy and safety of a widely used traditional Chinese medicine (Paeoniflorin (PAE) plus cervus and cucumis polypeptide injection (CCPI) using disease-modifying antirheumatic drugs (DMARD) as a control (methotrexate (MTX) plus leflunomide (LEF)). Patients were randomly assigned to one of the three groups: PAE + CCPI, MTX + LEF, and MTX + LEF + CCPI. The primary end point was the American College of Rheumatology 20% improvement response criteria (ACR20). The secondary end point was that of adverse effect frequencies and the speed of onset action. Our results showed that more patients in the CCPI-containing groups responded to the ACR20 during early treatment. After six months, ACR20 showed no significant difference among the three treatments. The maximum improvement in the two DMARD groups was significantly higher than that in the PAE + CCPI group (p < 0.01). CCPI made the onset action of the DMARD therapy 4.6 times faster. PAE + CCPI had significantly lower adverse event incidences than the two DMARD groups. These results indicate that PAE + CCPI appear to be a more acceptable alternative to DMARDs when patients cannot use DMARDs. CCPI appears to be a beneficial add-on to DMARDs that makes the onset of action faster, especially when patients need to relieve RA symptoms as soon as possible. Although not as effective as DMARDs, PAE appears to be a safer option to substitute DMARDs for long-term RA treatment when DMARD toxicity is an issue.
Trial registration: ClinicalTrials.gov NCT01600521.