Switching antidepressant (SSRIs to another SSRI) in adults

SSRIs to another SSRI

From all except fluoxetine

Direct switch

• a direct switch, i.e. stopping one antidepressant and then starting the new antidepressant the following day, is normally possible

From fluoxetine

• Taper, washout and switch
  • gradually reduce the dose of fluoxetine to 20mg daily and stop; wait 4 to 7 days before starting low dose SSRI
  • clinicians should decide the duration of the washout period on a case-by-case basis
    
    
• fluoxetine may still cause medicine interactions 5 or 6 weeks after stopping, as fluoxetine and its active metabolite have a long half-life

Reference:

• NHS Specialist Pharmacy Service (February 2023). SSRIs to other antidepressants: switching in adults