A 32-year-old patient with schizophrenia was staed on haloperidol 15 mg per day. A week later he was found to have high-grade fever, rigidity and the blood tests revealed leucocytosis and increased CPK levels. What is the usual cause of death in such patients?

History of use of a typical antipsychotic followed by symptoms of high-grade fever, rigidity and increase CPK levels and leucocytosis is suggestive of Neuroleptic malignant syndrome (NMS). The patients with NMS may develop rhabdomyolysis, resulting in myoglobinuria and that may cause acute renal failure