Serotonin Syndrome Induced by Sertraline, Fluvoxamine and Andrographis Interaction: a Case Report

Abstract

Serotonin syndrome is a condition characterized by excessive level of serotonin in the body, often caused by serotonin-selective receptor inhibitors (SSRIs), particularly when factors reduce the elimination of these drugs. This article reports on a 29-year-old Thai male with underlying conditions of schizophrenia and obsessive-compulsive disorder. His current medications included fluvoxamine 200 mg daily and sertraline 200 mg daily. Two days before presenting to the hospital, the patient developed a fever and self-medicated of six capsules of a herbal supplement, Andrographis paniculata (also known as Fah Talai Jone). As his symptoms did not improve, he sought medical attention. The physician suspected that fever, combined with hyperreflexia, resulted from serotonin syndrome, caused by the interactions of fluvoxamine, sertraline and Andrographis paniculata through the inhibition upon activities of the enzymes CYP1A2, CYP2C19, CYP2C9, CYP2D6, CYP3A, and CYP3A4. The patient was treated by discontinuing fluvoxamine and sertraline. Cyproheptadine 12 mg was administered immediately, followed by cyproheptadine 4 mg every 4 hours, and then reducing the dosage to cyproheptadine 4 mg every 8 hours. The patient's fever subsided, and laboratory tests results showed an improvement, cyproheptadine was discontinued. Identification of the causes and contributing factors of serotonin syndrome in patients receiving SSRIs or medications that increase serotonin levels, especially in combination with other drugs or herbal supplements, is essential. It is crucial to monitor and advise patients to recognize early symptoms and manage them promptly.