Related articles: Serotonin syndrome
Definition
Serotonin syndrome is a potentially life-threatening, usually drug-related condition.
This clinical picture derives from an increased serotoninergic activity in the central and peripheral nervous system.
Serotonin syndrome can occur as a result of the normal therapeutic use of some drugs, due to intoxication or involuntary drug interactions (if two serotonergic agents are taken at the same time).
The drugs that can cause this condition include: selective serotonin recovery (SSRI) inhibitors, monoamine oxidase inhibitors (MAOIs), serotonin and norepinephrine reuptake inhibitors, tricyclic antidepressants and opiates.
Serotonin syndrome may occur a few hours or days after treatment.
Symptoms can vary widely by severity and include:
- Changes in mental status : anxiety, hypomania, psychomotor agitation, restlessness, confusional states and delirium.
- Autonomic hyperactivity: increased heart rate (tachycardia), arterial hypertension, hyperthermia (fever), intense sweating (diaphoresis), chills, headache, vomiting and diarrhea.
- Neuromuscular hyperactivity : it can be more pronounced at the lower extremities compared to the upper ones and involves tremor, accentuated reflexes (hyperreflexia), hypertonia or muscular stiffness and myoclonus (muscular contractions).
Most common symptoms and signs *
- Hallucinations
- Chills
- Coma
- Convulsions
- Delirium
- Delirium tremens
- Depression
- Diarrhea
- Temperature
- Abdominal gurgling
- Hyperhidrosis
- hyperreflexia
- Hypertension
- Hypertonia
- Hypomania
- Hypoxia
- Restlessness
- Headache
- Mydriasis
- myoclonus
- Nausea
- Loss of coordination of movements
- Rhabdomyolysis
- Muscle spasms
- Confusional state
- Tachycardia
- Tremors
Further indications
Other pathological manifestations may be metabolic acidosis, rhabdomyolysis, convulsions, acute renal failure and disseminated intravascular coagulation.
The diagnosis can be made through the clinical evaluation of the patient and a thorough investigation of the symptoms. The distinction with neuroleptic malignant syndrome can be difficult, since many symptoms overlap (such as muscle stiffness, hyperthermia, autonomic hyperactivity and altered mental status). Indications in favor of a serotonergic syndrome include the use of serotonergic drugs, rapid onset (often within 24 hours) and hyperreflexia (in contrast to the decrease in reflexes that usually occurs in neuroleptic malignant syndrome) .
Patients must be subjected to tests that exclude other pathologies (eg ECG; examination of the cerebrospinal fluid to find a possible infection of the CNS; urinalysis for the search for drugs of abuse). Some investigations may be necessary to identify the presence of complications in severe serotonin syndrome (eg serum electrolytes, platelet count, renal function test and myoglobin research in urine).
The management of the serotonin syndrome involves the suspension of drugs that can help trigger and sustain the condition. An important supportive treatment involves sedation through the administration of benzodiazepines, mechanical ventilation and, if necessary, the administration of a serotonin antagonist. In case of malignant hyperthermia, it is necessary to cool the body.
Prognosis is usually good when adequate supportive treatment is adopted. However, deaths from multi-organ failure or brain anoxia have been reported.
