ABSTRACT
The use of dietary metabolic precursors to neurotransmitter in the management of chronic pain patients has received critical attention for several years. As pain evolves from acute to chronic, different neuronal pathways are used and diverse areas of the brain become involved in pain perception and modulation. The serotonergic system serves as a useful model for understanding the effect of metabolic precursors. Oral L-tryptophan administration decreases the perception of pain, appearing to act synergistically with the enkephalins and endorphins. Drugs that either increase the serotonin level or block reuptake are associated with decreased pain perception, increased pain threshold, and improved sleep. From a therapeutic standpoint, dietary modification would appear to be attractive, due to its low economic basis, decreased risk of addiction and dependence, as well as simplicity. However, potential risk from toxicity is only recently being recognized, along with difficulty in reliability of analgesic effect from one patient to another. Currently, L-tryptophan is unavailable for therapeutic use in the United States and is not recommended implicitly or explicitly by the author because of its potential health risk.
