Withdrawal syndrome after antipsychotics discontinuation: an analysis of the WHO database of spontaneous reports (Vigibase) between 2000 and 2022.

Rationale: Withdrawal syndrome (WDS) has been described after discontinuation of antipsychotics. WDS could be the consequence of an over-activation of the dopaminergic pathway. Antipsychotics with a higher affinity for dopamine D2 receptors could be associated with a higher risk of WDS. This study aims to address this statement and evaluate the risk difference for withdrawal syndrome between antipsychotics based on pharmacovigilance data.

Methods: We collected individual reports registered in Vigibase® between 01/01/2000 and 31/12/2022 of patients treated with antipsychotics and who had presented WDS. A disproportionality analysis was performed to evaluate the risk of reporting WDS with each antipsychotic compared to all other antipsychotics. We performed a correlation analysis to assess the correlation between the risk of reporting WDS for each antipsychotic in relation with their pKi for D2 and 5HT2A receptors.

Results: The most frequent psychiatric withdrawal symptoms after antipsychotic discontinuation were insomnia, anxiety and depression. Tremor, headache and dizziness were among the most frequently reported neurologic withdrawal symptoms. Tiotixene had the highest risk of reporting WDS (ROR 7.08; 95%CI 3.49 - 14.35) followed by pimozide (ROR 4.35; 95%CI 1.93 - 9.77), quetiapine (ROR 4.24; 95%CI 3.87 - 4.64), thioridazine (ROR 4.17; 95%CI 2.50-6.98) and ziprasidone (ROR 2.98; 95%CI 2.41-3.67). We found a poor correlation between D2/5HT2A binding affinity and the risk of reporting withdrawal syndrome (R = 0,094).

Conclusion: Our results suggest that there might be a risk difference for WDS between antipsychotics. Tiotixene, pimozide and quetiapine were associated with a higher risk of reporting a WDS whereas this risk was lower with chlorpromazine, clozapine and fluphenazine. We could not address the issue of withdrawal psychosis, withdrawal dyskinesia, rebound psychosis or supersensitivity psychosis due to the lack of specific WHO medDRA coded terms to identify potential cases.