Published: February 2010

Serotonergic agents and discontinuation syndrome - reminder

Prescriber Update 31(1): 6-7
February 2010

CARM continues to receive reports of “withdrawal symptoms” in patients following discontinuation of serotonergic medicines such as selective serotonin reuptake inhibitors (SSRIs).

While discontinuation syndrome is a recognised reaction that can occur following the abrupt cessation of serotonergic agents, prescribers are reminded that dose tapering may reduce the likelihood of symptoms occurring.1,2

Paroxetine and venlafaxine have been associated with discontinuation syndrome more often than the other serotonergic antidepressants; in the case of paroxetine this may be due, in part, to its shorter half life.3

Common symptoms associated with discontinuation syndrome include dizziness, paraesthesia, headache, anxiety, agitation, tremor, sweating, confusion and nausea. Symptoms can occur within a few days of discontinuation or may be delayed, particularly in the case of fluoxetine, due to its longer half-life. The majority of symptoms experienced on discontinuation are self-limiting, but can be distressing for patients.

To reduce the likelihood of discontinuation syndrome the dose of serotonergic agents should be reduced gradually over a period of several weeks or months. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the dose may continue to be decreased, but at a more gradual rate.

Further information is provided in the relevant product data sheets, available on the Medsafe website.

  1. Mylan New Zealand Limited. 2 Feb 09. Loxamine (paroxetine) data sheet
  2. Antidepressants. In Sweetman SC (ed) 2009. Martindale (36th Ed). Great Britain: Pharmaceutical Press. p. 372-430.
  3. Weller IVD. Report of the CSM Expert Working Group on the safety of selective serotonin reuptake inhibitor antidepressants. 2005. London: The Stationery Office.