Table 1.

Serotonergic drugs classified by mechanism of enhancing serotonin in synapses

Pharmacological action leading to increased serotonin level	Examples of drugs/drug groups
Increase in production of serotonin	Cocaine, L-tryptophan, phentermine
Increased release from presynaptic terminals	Tramadol, meperidine, oxycodone, phentermine, MDMA, mirtazapine, dextromethorphan, L-DOPA
Inhibition of serotonin reuptake	SSRIs, TCAs, SNRIs, opiates, cocaine, MDMA, dextromethorphan, chlorpheniramine, phentermine, bupropion, trazodone, nefazodone, ondansetron, granisetron, St. John’s Wort
Decrease/inhibit serotonin degradation	MAO inhibitors, triptans, buspirone, St. John’s Wort
Inhibition of microsomal oxidases (cytochrome-P450)	Fluconazole, citalopram, methadone, oxycodone, venlafaxine, ciprofloxacin, ritonavir, fluoxetine, sertraline, dextromethorphan, phentermine, tramadol, risperidone
Serotonin receptor activation	Lithium, buspirone, mirtazapine, trazodone, triptans, dihydroergotamine, fentanyl, meperidine, metoclopramide, LSD

The data for this table were acquired from different resources including, but not limited to, Buckley et al. and Volpi-Abadie et al. SSRIs=Selective serotonin reuptake inhibitors, TCAs=Tricyclic antidepressants, SNRI=Serotonin–norepinephrine reuptake inhibitors, MAO=Monoamine oxidase, MDMA=Methylenedioxymethamphetamine, LSD=Lysergic acid diethylamide