Objective To observe the clinical efficacy and safety of External Application of Xiaopi Zhentong Gao（ 消痞镇痛膏

XZG） combined with Oxycontin tablets in the treatment of severe pain of lung cancer. Methods Sixty patients suffering from severe pain of lung cancer were randomized into treatment group and control group with 30 cases in each group. The treatment group was given external application of WZG combined with oral Oxycontin tablets

while the control group was given external application of placebo combined with oral Oxycontin tablets. Both groups were treated for 7 days. The pain score

daily consumption of Oxycontin tablets

immune function index and constipation associated symptom score were observed before and after treatment

and the effect for pain was evaluated.Results The remission rate of pain in the treatment group was 90. 0%

higher than that in the control group（ 76. 7%

P < 0. 05）. After treatment

the daily consumption of Oxycontin tablets in the treatment group was lower than that in the control group（ P < 0. 05）. After treatment

the immune indexes of both groups improved compared with those before treatment

and the treatment group was superior to the control group（ P < 0. 01）; Karnofsky score in both groups significantly improved（ P < 0. 01） after treatment

but there was no significant difference between groups（ P > 0. 05）; the incidence of side effects in the treatment group was significantly lower than that in the control group（ P < 0. 05）

and the constipation associated symptom score in the treatment group was significantly lower than that in the control group（ P < 0. 01）. Conclusion XZG seems have synergistic effects with Oxycontin tablets

enhancing its effect and reducing its toxicity. XZG could effectively reduce cancer pain

reduce the daily consumption of Oxycontin tablets and the side effects

improve the immune function of patients and improve their quality of life.