Qianggu capsule for the treatment of primary osteoporosis: evidence from a Chinese patent medicine

Background: Qianggu Capsule, a Chinese patent medicine, has been widely applied in the clinical practice of primary osteoporosis (POP) in recent years. This study aims to summarize the effectiveness and safety of Qianggu Capsule in treating POP. Methods: We searched seven electronic databases, all searches ended in 30 September, 2015. All randomised controlled trials comparing the efficacy of Qianggu Capsule treatment with no treatment, placebo or conventional therapy for POP were included. Combined therapies of Qianggu Capsule were also included. Cochrane risk of bias tool was used to assess methodological quality of primary studies. Revman 5.2.0 software was used for data analysis. Results: Ten trials were enrolled. The combined effect showed that Qianggu Capsule plus Caltrate D was better than Caltrate D on lumbar spine bone mineral density (BMD) (MD = 0.05 g/cm(2); 95% CI: 0.02-0.07; P = 0.0004), femoral neck BMD (MD = 0.03 g/cm(2); 95% CI: 0.01-0.05; P = 0.001), femoral great trochanter BMD (MD = 0.04 g/cm(2); 95% CI: 0.03-0. 06; P < 0.001). Meta-analysis exhibited a significant antiosteoporosis effect of Qianggu Capsule on femoral neck BMD (MD = 0.03 g/cm(2); 95% CI: 0.01-0.05; P = 0.003) and femoral trochanteric BMD (MD = 0.07 g/cm(2); 95% CI: 0.02-0.12; P = 0.006) compared with alpha-D3 capsule. However, the methodological quality of included studies was low. Constipation and dry mouth were the most common adverse drug reactions of Qianggu Capsule. Finally the evidence level was evaluated to be low or very low. Conclusions: The effect of Qianggu Capsule for POP was supported in improving BMD. Due to the methodological drawbacks of the included studies, the conclusions should be treated with caution for future research.