Serotonin Syndrome

A condition when one takes medication (serotonergic agents/medications/drugs) that increase serotonin levels (Serotonin is a chemical your body produces that’s needed for your nerve cells to regulate temperature, mood and social behaviour, breathing, appetite and digestion, sleep/wake cycle, memory, sexual desire , muscle tone, , blood clotting, uterine contractions, and brain to function) in ones body due to an:

• Increase the dose of such serotonergic agents/medications/drugs or add a new serotonergic agents/medication/drug for your condition
• An over dose of serotonergic agents/medications/drugs
• Serotonergic agents/medication/drugs that cause high levels of the chemical serotonin   to accumulate in your body.
• A combination of serotonergic agents/medications or drugs
• An increase in therapeutic dosing of a serotonergic agents/medication/drugs
• An overdose or inadvertent interactions of serotonergic agents/medication/drugs

Milder forms of serotonin syndrome may go away within a day of stopping the medications that cause symptoms and, sometimes, taking medications that block serotonin.

Diagnosis Tests

• No specific laboratory test is indicated to diagnose serotonin syndrome, and serotonin levels do not correlate with the severity of symptoms. The Hunter criteria are the most accurate diagnostic set available to diagnose serotonin syndrome, with 84% sensitivity and 97% specificity. The criteria require that a patient be taking a serotonergic agent and meet at least one of the following conditions^[4]:
• Spontaneous clonus (involuntary muscle contractions)
• Inducible clonus with agitation or diaphoresis (inducing muscle contractions via muscle tests done by a medical trained professional with with a change of behaviour (irritated, anxiety, and/or depression) or sweating]
• Ocular clonus with agitation or diaphoresis [abnormal eye movement with a change of behaviour (irritated, anxiety, and/or depression) or sweating]
• Tremor and hyperreflexia (overactive or overresponsive reflexes)
• Hypertonia, temperature greater than 38°C (100.4°F) , and ocular clonus (abnormal eye movement) or inducible clonus  (Uncontrollable, rhythmic, shaking movements)

EJ, Isbister GK, Sibbritt D, Dawson AH, Whyte IM. The Hunter serotonin toxicity criteria: simple and accurate diagnostic decision rules for serotonin toxicity. QJM. 2003;96:635.

Medscape

SHIVERS pneumonic for screening for serotonin syndrome

S hivering – helps distinguish serotonin syndrome from other hyperthermic syndromes

H yperreflexia and myoclonus (brief involuntary twitching or jerking of a muscle or group of muscles) are common in mild-to-moderate cases; muscular rigidity in severe cases

I ncreased temperature

V ital sign instability — for example, tachycardia (fast heartbeat), tachypnea (fast shallow breathing), and/or labile blood pressure (no symptoms o rcan be accompanied by symptoms such as headache, palpitations, or flushing).

E ncephalopathy — notable change in mental state; for example, agitation, delirium (medical emergency), confusion

R estlessness owing to excess serotonergic activity

S weating — distinguishing feature of serotonin syndrome; for example, in neuroleptic malignant, the skin feels hot but dry

Adapted from: MDedge Psychiatry

Christensen R. Get serotonin syndrome down cold with SHIVERS. MDedge. 2006.
https://www.mdedge.com/psychiatry/
article/62032/
get-serotonin-syndrome-down-cold-shivers (accessed Feb 2023).