What clinical analysis of antipsychotic-induced catatonia and neuroleptic malignant syndrome tells us about the links between these two syndromes: A systematic review.

OBJECTIVES: Antipsychotic-induced catatonia (AIC) and neuroleptic malignant syndrome (NMS) are life-threatening adverse reactions to antipsychotic medication. We conducted a systematic review of literature following the PRISMA statement guidelines to obtain a description of these syndromes (population, context of occurrence, antipsychotic agents implicated) and draw conclusions about their links. METHODS: We searched Medline and Web of science databases from January 1951 to May 2019 (further restricted from 2000 to 2019) using search terms including "catatonia", "neuroleptic malignant syndrome" and "antipsychotic agents" for case reports, case series and analytic studies. After screening 4082 records, 410 full-text articles (describing 555 events) were assessed for eligibility. We included events of AIC and/or NMS according to Diagnostic and Statistical Manual (DSM) criteria and extracted data about patients' characteristics, context of occurrence, antipsychotic agent(s) involved and treatment outcomes. RESULTS: We included 165 events (16 AIC, 129 NMS and 20 AIC + NMS) from 144 case reports and case series. The most reported diagnosis was schizophrenia. Comorbid pre-existing conditions such as central nervous system diseases and acute medical events were common. Most of the events (63.3 %) occurred during antipsychotic monotherapy. Second-generation antipsychotics (SGAs, 63.8 %) were overall more implicated than first-generation antipsychotics (FGAs, 36.2 %). DISCUSSION: Our findings highlight that any antipsychotic medication, even SGA monotherapy prescribed at recommended dose, is at risk for these side effects. FGAs and polypharmacy seem to represent risk factors for malignant catatonia in AIC. The clinical overlap observed between AIC and NMS events in our review suggests a clinical continuum between catatonia and NMS.

Comparative Effects of 30 Antipsychotics on Risk of Catatonia: An Analysis of the WHO Pharmacovigilance Database.

Objective: Catatonia is a life-threatening psychomotor syndrome that occurs in approximately 10% of patients with acute psychiatric illnesses. Although some case reports have argued that first generation antipsychotics (FGAs) are more likely to induce catatonia than second generation antipsychotics (SGAs), no large observational study has confirmed this hypothesis. We investigated whether FGAs were associated with an increased risk of reporting catatonia when compared with SGAs.Methods: A pharmacovigilance study was performed within VigiBase to compare the cases of catatonia syndromes reported in patients exposed to FGAs with those reported in patients exposed to SGAs. This approach is similar in concept to case-control study, but adapted to a pharmacovigilance database, and allows the estimation of reporting odds ratios (RORs) with 95% confidence intervals.Results: We identified 60,443 adverse effects reported in patients who received FGAs and 253,067 adverse effects reported in patients treated with SGAs. Compared with SGAs, the use of FGAs was associated with an increased risk of reporting catatonia syndromes (ROR = 2.2; 95% CI, 2.0-2.3). Consistent results were observed when the analysis was restricted to reports generated from physicians, reports from the US, and reports with the highest completeness score. The highest RORs were found for molindone (6.0; 95% CI, 3.1-10.4) and haloperidol (3.8; 95% CI, 3.5-4.0).Conclusions: In this large pharmacovigilance study of patients exposed to antipsychotics, the use of FGAs was associated with an increased risk of reporting catatonia syndromes compared to the use of SGAs. This increased risk is consistent with the pharmacodynamic hypothesis of antipsychotic-induced catatonia. Our results warrant replication in population-based studies.