LIDTKE Medical

Hunter Serotonin Toxicity Criteria

L-Tryptophan occasionally is prescribed concurrently with SSRI's such as Prozac, Paxil, Zoloft, or Effexor, but some doctors prefer to follow a procedure that substitutes L-Tryptophan for the SSRIs. This process may take several weeks, and symptoms should to be monitored by a doctor to avoid swings in serotonin levels. L-Tryptophan should not be given, however, with MAO Inhibitors.

The test for excess serotonin, called the Hunter Serotonin Toxicity Criteria that should be used as an evaluation tool by doctors. As a general rule, L-Tryptophan can be substituted for other serotonergic agents, but a gradual process of substitution, typically lasting three weeks or more, should be followed, depending on the “washout period”, strength of interaction of drugs with L-Tryptophan, and symptoms of the patients.

Hunter Serotonin Toxicity Decision Rules:
In the presence of a serotonergic agent

  1. IF [spontaneous clonus = yes] THEN [Serotonin toxicity = YES]

2. ELSE, IF [inducible clonus = yes] AND [[agitation=yes] OR [diaphoresis=yes]]
    THEN [serotonin toxicity = YES]

3. ELSE, IF [ocular clonus = yes] AND [[agitation = yes] OR [diaphoresis = yes]]
    THEN [serotonin toxicity = YES]

4. ELSE IF [tremor = yes] AND [hyperreflexia = yes]
    THEN [serotonin toxicity = YES]

5. ELSE IF [hypertonic = yes] AND [temperature > 38°C] AND [[ocular clonus = yes]                
    OR [inducible clonus = yes]] THEN [serotonin toxicity = YES

6. ELSE [serotonin toxicity = NO]

Your doctor should be able to use these rules to make sure you do not become serotonin toxic.