Effect of diclofenac on the antiallodynic activity of vitamin B12 in a neuropathic pain model in the rat.

B vitamins have been used as analgesic drugs to treat pain disorders associated with their deficiency. More recently it has been claimed that B vitamins are useful to relieve different pain states as carpal tunnel, migraine and premenstrual tension. In Latin America, B vitamins are commonly used to treat neuropathic pain; however, there is no data to support this indication.