From the Guidelines
Serotonin syndrome is a life-threatening condition characterized by a classic triad of symptoms, including altered mental status, autonomic instability, and neuromuscular abnormalities, and requires immediate medical attention. The symptoms of serotonin syndrome can vary, but the most common signs and symptoms include:
- Altered mental status, such as confusion, agitation, anxiety, and hallucinations
- Autonomic instability, including high fever, sweating, rapid heart rate, high blood pressure, and dilated pupils
- Neuromuscular abnormalities, such as tremor, muscle rigidity, hyperreflexia, and clonus, especially in the lower limbs
- Other common signs, including shivering, diarrhea, headache, and in severe cases, seizures and loss of consciousness According to the study by 1, the clinical triad of serotonin syndrome consists of mental status changes, autonomic hyperactivity, and neuromuscular abnormalities, and the diagnosis can be made if the patient has taken a serotonergic drug within the last 5 weeks and has any of the following: tremor and hyperreflexia; spontaneous clonus; muscle rigidity, temperature >38°C, and either ocular clonus or inducible clonus; ocular clonus and either agitation or diaphoresis; or inducible clonus and either agitation or diaphoresis. The study by 1 also highlights that serotonin syndrome can be triggered when serotonergic medications are combined, and symptoms can arise within 24 to 48 hours after combining medications, characterized by mental status changes, neuromuscular hyperactivity, and autonomic hyperactivity. It is essential to seek immediate medical attention if serotonin syndrome is suspected, as it can progress rapidly and become life-threatening, with treatment involving discontinuing the offending medications and providing supportive care, with severe cases requiring serotonin antagonists like cyproheptadine, as recommended by 1 and 1.
From the Research
Signs and Symptoms of Serotonin Syndrome
The signs and symptoms of serotonin syndrome can be categorized into three main areas:
- Neuromuscular excitation, such as tremor, hyperreflexia, and clonus 2, 3
- Autonomic dysfunction, including tachycardia, hypertension/hypotension, and hyperthermia 2, 3
- Altered mental status, such as agitation, delirium, and coma 2, 3
Additional Symptoms
Other symptoms that may be present in serotonin syndrome include:
- Agitation 4
- Confusion 4
- Rapid heart rate 4
- High blood pressure 4
- Dilated pupils 4
- Muscle rigidity 4
- Tremors 4
- Sweating 4
- Diarrhea 4
- Myoclonus 5
Severity of Symptoms
The severity of symptoms can range from mild to severe, and in some cases, serotonin syndrome can be life-threatening 2, 3, 6. It is essential to recognize the signs and symptoms of serotonin syndrome to provide prompt and effective treatment.