MECHANISM OF SEROTONIN SYNDROME
(1) Increased doses of L-tryptophan will proportionally increase 5-hydroxytryptamine (5-HT or serotonin) formation. (2) Amphetamines and other drugs increase the release of stored serotonin. (3) Inhibition of serotonin metabolism by monoamine oxidase (MAO) inhibitors will increase presynaptic 5-HT concentration. (4) Impairment of 5-HT transport into the presynaptic neuron by uptake blockers (e.g., selective serotonin reuptake inhibitors, tricyclic antidepressants) increases synaptic 5-HT concentration. (5) Direct serotonin agonists can stimulate postsynaptic 5-HT receptors. (6) Lithium increases postsynaptic receptor responses.