Delirium Associated With Fluoxetine Discontinuation: A Case Report

Area of Science:

• Neuroscience
• Psychiatry
• Clinical Pharmacology

Background:

• Selective serotonin reuptake inhibitors (SSRIs) are commonly used for major depressive disorder.
• SSRI discontinuation syndrome is a recognized clinical phenomenon, typically involving various withdrawal symptoms.
• Delirium is an uncommon manifestation of SSRI discontinuation syndrome.

Observation:

• A 65-year-old female with major depressive disorder developed delirium after the gradual discontinuation of fluoxetine.
• The patient's delirious symptoms improved upon reintroduction of a low dose of fluoxetine.
• Subsequent dose adjustments of fluoxetine and olanzapine led to resolution of psychotic symptoms without recurrence of delirium.

Findings:

• This case illustrates a rare presentation of delirium as a complication of fluoxetine discontinuation.
• The rapid decrease in serotonin availability is implicated in SSRI discontinuation syndrome.
• Factors such as medication half-life and potential genetic vulnerability may influence the occurrence and rapidity of SSRI discontinuation symptoms.

Implications:

• Clinicians should consider delirium in patients experiencing SSRI discontinuation, even with long-half-life agents like fluoxetine.
• Gradual tapering of SSRIs may be crucial to mitigate discontinuation symptoms, including rare complications like delirium.
• Further research into genetic polymorphisms may elucidate individual susceptibility to SSRI discontinuation syndrome.