Antidepressant stopping & switching

Warning

Stopping

All antidepressants can cause discontinuation symptoms with the possible exceptions of agomelatine and vortioxetine.

Abrupt withdrawal should be avoided unless a serious adverse event has occurred.

Reduce dose gradually over 4 weeks (except fluoxetine due to its long half-life), this is particularly important in drugs with a short half-life (e.g. paroxetine and venlafaxine).

Discontinuation symptoms (these can be drug specific, consult individual SPC for further information) include:

  • Agitation
  • Flu-like symptoms
  • Headache
  • Insomnia
  • Irritability
  • Shock-like sensations
  • Vivid/excessive dreaming

Symptoms are usually mild and self-limiting but in some cases may be severe and prolonged.

Ensure patients are given adequate education on the symptoms they are likely to experience, onset and duration.

Switching

Cross-tapering is preferred when switching from one antidepressant to another:

  • Dose of current antidepressant is reduced slowly while slowly introducing the new antidepressant
  • Speed of cross-tapering should be based on individual patient tolerability
  • Not suitable for all situations (see table for further information)

Risks associated with cross-tapering include:

  • Pharmacodynamic interactions
    • Serotonin syndrome
    • Hypotension
    • Drowsiness
  • Pharmacokintetic interactions
    • Increased plasma levels of tricyclics by some SSRIs
  • Antidepressant discontinuation symptoms
    • Could be mistakenly interpreted as side effects of new medication

Symptoms of serotonin syndrome include (see full guidance for management):

  • Confusion
  • Convulsions
  • Myoclonus
  • Restlessness
  • Shivering

The table within the full guidance sets out guidance for specific drug to drug switches. Contact local clinical pharmacy services for additional advice.

 

Editorial Information

Last reviewed: 10/05/2022

Next review date: 01/12/2024

Author(s): PMG-MH.

Version: 1

Author email(s): PrescribingManagementGroup.MentalHealth@ggc.scot.nhs.uk.

Approved By: PMG-MH

Reviewer name(s): Lead Clinical Pharmacist, Clinical Effectiveness Pharmacist.