Serotonin syndrome in a Parkinson disease patient after intake of an ethanol-containing homeopathic medication

Serotonin syndrome is due to excess serotonin in the nervous system. We document a case of an elderly Parkinson disease patient who has been neurologically stable on rasagiline and escitalopram for 1 year but developed serotonin syndrome after intake of an ethanol-containing homeopathic medication. The patient presented with seizures, autonomic dysfunction and neuromuscular hyperexcitability. Maintenance medications were discontinued, hydration, sedation and respiratory support were provided with resolution of the symptoms. The combination of escitalopram and ethanol, both metabolized by the cytochrome P450 enzyme system can lead to serotonin syndrome. Our case highlights the importance of drug interactions in patients taking several medications. Additionally, the intake of medicines, may it be conventional or homeopathic medicine, without the guidance of a trained and competent physician, may lead to serious consequences for the patient.