Medication-induced Serotonin Syndrome

Abstract

The increased prevalence of depression worldwide was amplified with COVID-19 pandemic which triggered 25% increase in prevalence of anxiety and depression (WHO 2022), with consequential increased use of antidepressants, associated with adverse reactions such as serotonin syndrome (SS) and their use in acute poisonings. Increased prescription of serotonin re-uptake inhibitors was registered in North Macedonia during last four years. SS is a potentially life-threatening clinical condition associated with increased serotonergic activity in the central nervous system. It is induced by certain herbs, medications in therapeutic doses and unintentional drug interactions as well as with psychoactive substances and self-poisoning. Clinically is presented as a triad of changes in mental status, autonomic hyperactivity and neuromuscular abnormalities, with prognosis ranging from benign to lethal. The diagnosis is based on medical history and clinical presentation. The signs appear within 24 hours, usually within the first 6 hours of initiating therapy. Typical clinical signs are tachycardia and hypertension, but in severe cases hyperthermia and dramatic changes in pulse, blood pressure, mental status, neuromuscular aberrations and DIC may develop. Diagnosis is made using Hunter's criteria for serotonin toxicity. Differential diagnoses of SS include ischemic brain events, meningoencephalitis, neuroleptic malignant or anticholinergic syndrome, malignant hyperthermia, intoxication by sympathomimetic agents, benzodiazepine withdrawal syndrome. The treatment of serotonin toxicity depends on the severity of the clinical presentation (mild, moderate, severe) and ranges from symptomatic to administration of 5-HT2 receptor antagonists (Cyproheptadine) and artificial ventilation. Thinking of SS helps us to avoid the inability to recognize the syndrome, misdiagnosis and late treatment considering the fast rate of SS progression.