Increased risk of occurrence of neuroleptic malignant syndrome on combined treatment with lithium and neuroleptic

Whether there is an increased risk of occurrence of neuroleptic malignant syndrome (NMS) on combined treatment with lithium and neuroleptic is a controversial issue. Patients seen in a general psychiatry unit of a university hospital in India were prospectively screened for NMS over a 2 year period. Diagnosis of NMS was made on operational criteria and the details of treatment at the time of occurrence of NMS were collected systematically. Eight cases of NMS were identified during the period of the study, out of which 5 (62.5%). were taking lithium and a neuroleptic together at the time of occurrence of NMS. The high prevalence of patients on lithium and neuroleptic concomitantly in our sample of NMS, and the similar findings in many of the earlier prospective studies, makes it possible to speculate whether there is an association between combined use of lithium and neuroleptic and occurrence of NMS. Findings are discussed.