Serotonin Syndrome

Serotonin syndrome is a potentially life-threatening drug reaction that may occur following therapeutic drug use, inadvertent interactions between drugs, overdose of particular drugs, or the recreational use of certain drugs. Serotonin syndrome is not an idiopathic drug reaction; it is a predictable consequence of excess serotonergic activity at central nervous system (CNS) and peripheral serotonin receptors. For this reason, some experts strongly prefer the terms serotonin toxicity or serotonin toxidrome because these more accurately reflect the fact that it is a form of poisoning

Other information: Mayo Clinic
Symptoms^: 

• Cognitive effects: headache, agitation, hypomania, mental confusion, hallucinations, coma
• Autonomic effects: shivering, sweating, hyperthermia, hypertension, tachycardia, nausea, diarrhea.
• Somatic effects: myoclonus (muscle twitching), hyperreflexia (manifested by clonus), tremor.

Cause

A large number of medications either alone in high dose or in combination can produce serotonin syndrome.

Class	Drugs
Antidepressants	Monoamine oxidase inhibitors (MAOIs), TCAs, SSRIs, SNRIs, Ibupropion, nefazodone, trazodone, mirtazapine
Opioids	tramadol, pethidine, fentanyl, pentazocine, buprenorphine, oxycodone, hydrocodone
CNS stimulants	MDMA, MDA, phentermine, diethylpropion, amphetamine, sibutramine, methylphenidate, methamphetamine, cocaine
5-HT1 agonists	triptans
Psychedelics	5-Methoxy-diisopropyltryptamine, LSD
Herbs	St John's Wort, Syrian rue, Panax ginseng, Nutmeg, Yohimbe
Others	tryptophan, L-Dopa, valproate, buspirone, lithium, linezolid, dextromethorphan, 5-hydroxytryptophan, , chlorpheniramine, risperidone, olanzapine, ondansetron, granisetron metoclopramide,, ritonavir