Lidocaine is a local anesthetic, which means that it causes temporary numbness when applied to a part of the body. Lidocaine is often used in trigger-point injections to alleviate pain in a specific area. It can also be given intravenously for treating widespread pain.
In fibromyalgia, some early research suggested that intravenous lidocaine may be effective against fibromyalgia pain. However, later research found no positive effects.
Trigger-point injections using lidocaine are a common treatment for myofascial pain syndrome, which frequently overlaps with fibromyalgia.
Schafranski MD, et al. Clinical rheumatology. 2009 Jul;28(7):853-5. Intavenous lidocaine for fibromyalgia syndrome: an open trial.
Vlainish R, et al. Pain practice. 2010 Jul-Aug;10(4):301-5. Effect of intravenous lidocaine on manifestations of fibromyalgia.
Vlainish R, Issy AM, Sakata RK. Clinical journal of pain. 2011 May;27(4):285-8. Effect of intravenous lidocaine associated with amitriptyline on pain relief and plasma serotonin, norepinephrine, and dopamine concentrations in fibromyalgia.