Synergistic effect of the association between lidocaine and magnesium sulfate on peri-operative pain after mastectomy: A randomised, double-blind trial.

Background: Recently, the use of venous adjuvants, such as lidocaine and magnesium sulfate, has been gaining ground in multimodal analgesia. However, no study has evaluated the impact a combination of the two drugs.

Objectives: To evaluate the efficacy of venous adjuvants in reducing opioid consumption and pain scores after mastectomy.