Q: What are the six different types of mechanism for Serotonin Syndrome (SS). Give at least one example of each with  commonly used drug which can precipitate SS?


Answer: Serotonin Syndrome can occur via six ways 

1. Increases serotonin formation -  Tryptophan

2. Increases release of serotonin  - Levodopa

3. Impairs reuptake from the synaptic cleft into the presynaptic neuron - Cocaine, MDMA, Meperidine, Tramadol, selective serotonin reuptake inhibitors (SSRIs)

4. Inhibits serotonin metabolism -  Monoamine oxidase inhibitors e.g linezolid

5. Direct serotonin agonist -  Buspirone,  Fentanyl 

 6. Increases sensitivity of postsynaptic receptor - Lithium

Reference:

Boyer EW, Shannon M. The serotonin syndrome. NEJM 2005; 352:1112.