A study from the UK examined 67 cases of neuroleptic malignant syndrome and 254 controls (1). The researchers made several interesting findings, in particular that patients on 3 or more antipsychotics had an odds ratio of 5.4 for NMS. This, along with evidence for increased risk of diabetes in patients on multiple antipsychotics (2), give reason to be cautious about antipsychotic polypharmacy.
1. Retrospective chart review on exposure to psychotropic medications associated with neuroleptic malignant syndrome. Su Y-P, Chang C-K, Hayes RD, et al. Acta Psychiatr Scand. Published online 15 November 2013. Abstract
2. Treatment with antipsychotics and the risk of diabetes in clinical practice. Kessing LV, Thomsen AF, Mogensen UB, Andersen PK. Br J Psychiatry. 2010;197:266–271. Full text