prevention of discontinuation syndrome

Last edited 05/2018

  • Prevention
    • Tapering after successful treatment
      • Recommendations on taper length vary
        • has been suggested that antidepressants administered for 8 weeks or more should, wherever possible, be reduced over a 4-week period
        • NICE suggest that
          • normally, gradually reduce the dose over 4 weeks (this is not necessary with fluoxetine). Reduce the dose over longer periods for drugs with a shorter half-life (for example, paroxetine and venlafaxine)

      • routine tapering is probably unnecessary when antidepressants have been prescribed for less than 4 weeks, as discontinuation symptoms are unlikely to occur with such a short duration of treatment (2)
      • an abruption of an antidepressant is justified if a patient has developed serious side effects believed to be due to the antidepressant, there is a medical emergency warranting stopping the antidepressant or the antidepressant has induced mania (2)

    • Tapering and antidepressant switching
      • data imply that if tapering SSRIs and venlafaxine is beneficial in reducing discontinuation symptoms, then it needs to continue for more than 14 days for most patients.
      • a start-taper switch refers to starting the new antidepressant and simultaneously gradually tapering the previous one
        • whether an abrupt switch or start-taper switch is chosen partly depends on the likelihood of discontinuation symptoms occurring, which in turn depends on the pharmacological similarity between the two antidepressants
      • using a washout period (no antidepressant prescribed)
        • is essential when switching to and from MAOIs because of the risk of drug interactions that can lead to serotonin syndrome
        • a washout should also be considered when switching from fluoxetine to a TCA, as the long-half life of fluoxetine, plus its ability to inhibit cytochrome P450 enzymes, could result in elevation of plasma TCA levels, leading to adverse effects (2)

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