Prolonged neuroleptic malignant syndrome after Haloperidol injection

Neuroleptic malignant syndrome (NMS) is a rare disorder caused by drug-induced dopamine-receptor-blockage or low dopamine concentration in the brain. It is a severe reaction to neuroleptic drugs in antipsychotic therapy. Symptoms in NMS typically consist of fever, muscle rigidity and cognitive changes; laboratory findings include elevated infectious disease markers and creatine kinase as well as signs of rhabdomyolysis. To differentiate NMS from other malignant hyperthermia syndromes identifying the offending drug and clinical history are essential. Therapy in NMS includes withdrawal of the causative medication and intensive care treatment possibly with administration of dantrolene.In this case report, we describe the clinical course of a 48 year old man who developed typical clinical symptoms and laboratory parameters of malignant hyperthermia syndrome after injection of haloperidol.