Evaluating the risk of mild serotonin syndrome in primary care: a retrospective case series of patients with treatment-resistant depression.

Background: Serotonin syndrome is an adverse drug reaction characterised by the excess of serotonin activity in the central nervous system. It is a condition of great concern in primary care where some patients, usually with treatment-resistant depression, get treatment with multiple serotonergic agents. Case Description: This retrospective case series looked at 20 primary care patients with treatment-resistant depression who developed mild serotonin syndrome after starting a second antidepressant. The patients were, on average, 40.4 years old, with 55% being female, and had been in treatment for about 5.3 years. The study also considered other health conditions and medications the patients were using. Interventions included stopping or reducing the dose of the second antidepressant, adjusting medications, and educating the patients. Symptoms occurred 1 to 4 weeks after introduction of the second antidepressant, with duration before presentation to the primary care physician ranging from 2 to 11 weeks. Symptoms resolved between 7-21 days after interventions for all patients, and 85% of cases were resolved in under 2 weeks. The most common intervention was stopping or reducing the dose of serotonergic medications in 70% of cases. All patients had improved, with an excellent response to well-targeted interventions in the primary care setting. Conclusions: This study highlights the need for careful monitoring of serotonin syndrome in patients with treatment-resistant depression, especially in the case of polypharmacy. Early recognition of symptoms by primary care providers and close management ensure patient safety through proper medication management and education.