Tapering/Switching Antipsychotics

Antipsychotics may be tapered or switched due to clinical reasons. There are no published controlled trials on switching antipsychotics, guidelines therefore are only an aid and not necessarily supported by evidence. The risk of antipsychotic discontinuation is significant in primary psychotic disorders (See: Antipsychotics - Length of Treatment)

• Withdrawal-emergent dyskinesia (W-ED) are moderate abnormal movements have been reported to occur from antipsychotic withdrawal in persons without a history of persistent tardive dyskinesia.^[1][2] This phenonemon is not well studied, and some studies have found an incidence of up to 30% of individuals that discontinue antipsychotics.
• W-ED typically occurs within 4 to 6 weeks of antipsychotic discontinuation, and resolves within 1 to 3 months of onset.^[3] Short-term management includes watchful waiting with reassurance in mild cases, while short-term symptomatic treatment includes clonazepam or reintroduction of the same antipsychotic, followed by more gradual taper or cross-taper.

Antipsychotic withdrawal symptoms may include nausea and vomiting, abdominal pain, diarrhea, headache, tachycardia, vertigo, increased perspiration, dry mucous membranes, myalgia, restlessness, anxiety, tension, insomnia, and hyperkinesia.^[4]

Several jurisdictions and organizations have published recommendations on how to switch/taper antipsychotics.

• Moncrieff, J., Crellin, N., Stansfeld, J., Cooper, R., Marston, L., Freemantle, N., ... & Priebe, S. (2023). Antipsychotic dose reduction and discontinuation versus maintenance treatment in people with schizophrenia and other recurrent psychotic disorders in England (the RADAR trial): an open, parallel-group, randomised controlled trial. The Lancet Psychiatry.
• Horowitz, M. A., Murray, R. M., & Taylor, D. Tapering Antipsychotic Treatment. JAMA psychiatry.
• Barriers to stopping neuroleptic (antipsychotic) treatment in people with schizophrenia, psychosis or bipolar disorder

• Burns, T., Chabannes, J. P., & Demyttenaere, K. (2002). Switching antipsychotic medications: general recommendations and switching to amisulpride. Current medical research and opinion, 18(4), 201-208.

• Reconsidering Medication Discontinuation After a First Episode of Psychosis - Dr. Robert Zipursky