A nurse is caring for a client who has major depressive disorder and was recently started on a SSRI. Which of the following assessment findings indicates a toxic effect related to the SSRI?

Selective serotonin reuptake inhibitors (SSRIs) are commonly used antidepressants that increase serotonin levels in the central nervous system by blocking its reuptake at synaptic junctions. Although generally safe, they can produce adverse effects, and in toxic states may contribute to serotonin syndrome. This condition results from excessive serotonergic activity affecting the autonomic nervous system, neuromuscular function, and mental status. Nurses must recognize early signs of toxicity to prevent serious complications. Rationale: A. Xerostomia (dry mouth) is a common and mild side effect of SSRIs due to their mild anticholinergic-like effects. It is uncomfortable but not indicative of toxicity or overdose. Clients may experience this early in therapy, and it is managed with hydration, oral hygiene, and sugar-free gum. B. Bradycardia is not typically associated with SSRI toxicity. In serotonin syndrome, autonomic instability is more commonly seen as tachycardia rather than slowed heart rate. Therefore, bradycardia does not represent a toxic effect of SSRIs. C. Hypothermia is not a characteristic finding of SSRI toxicity. Instead, serotonin syndrome often presents with hyperthermia due to increased neuromuscular activity and autonomic dysregulation. A decreased body temperature would not align with serotonergic excess. D. Hypertension is a key autonomic manifestation of SSRI toxicity, particularly in serotonin syndrome. Excess serotonin leads to increased sympathetic nervous system activity, resulting in elevated blood pressure, tachycardia, and possible hyperthermia. This finding requires immediate intervention and discontinuation of the offending agent.