Serotonin Toxicity (Hunter Criteria)
Hunter Serotonin Toxicity Criteria (Dunkley 2003): a five-branch decision rule for serotonin toxicity in a patient on a serotonergic agent.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Patient has taken a serotonergic agent
- Yes
- Spontaneous clonus
- Yes
Result: Meets Hunter criteria for serotonin toxicity (spontaneous clonus).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Spontaneous clonus
- Meets criteria for serotonin toxicity.
- Inducible or ocular clonus
- Meets criteria when accompanied by agitation or diaphoresis.
- Tremor + hyperreflexia
- Meets criteria.
- Hypertonia + temp over 38 C + clonus
- Meets criteria (the hyperthermic limb).
- No qualifying branch
- Does not meet criteria; reconsider the differential.
What you enter
- Patient has taken a serotonergic agent (required precondition)
- Spontaneous clonus
- Inducible clonus
- Ocular clonus
- Agitation
- Diaphoresis
- Tremor
- Hyperreflexia
The other 2 fields
- Hypertonia
- Temperature over 38 C
How this is calculated
Dunkley EJC, 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(9):635-642. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.