Atypical Neuroleptic Malignant Syndrome: Pitfalls and Challenges in the Delirious Substance Abuser

Abstract

Introduction: A rare and atypical form of Neuroleptic Malignant Syndrome (NMS) can be a deceptive and life threatening condition if not diagnosed properly in acute and critical care settings. Methods: The management of a patient presenting with atypical NMS without prominent rigidity, but with extensive rhabdomyolysis after the administration of haloperidol and ziprasidone is described in this report. Results: Prompt recognition of atypical features of NMS was managed by intensive care unit admission, supportive care and pharmacotherapy, leading to a complete resolution of the syndrome and a favorable outcome verified by laboratory findings. Conclusion: Early stages and atypical features of NMS may be variable in presentation and clinical course. The absence of muscle rigidity may not rule out NMS. A strong clinical suspicion based on clinical history is crucial for early diagnosis and treatment. Termination of dantrolene therapy may not be necessary during rhabdomyolysis and elevated aminotransferase levels.

Atypical neuroleptic malignant syndrome. “Doing more harm than gain”

“…In over 80% of cases altered mental status presenting as delirium, catatonia or agitation is the first sign of NMS before any systemic signs appear. 3 Cases without fever and/or absence of rigidity or only mild rigidity have also been described especially with atypical antipsychotic drugs. 4 Patients with delirium in acute care settings are generally treated with antipsychotics which continue to be the initial choice in the working guidelines.…”

“…4 Patients with delirium in acute care settings are generally treated with antipsychotics which continue to be the initial choice in the working guidelines. 3 In the critical care setting where concomitant use of sedatives may obscure the early signs of NMS, it becomes a tricky situation for the clinician to deal with. NMS if undiagnosed may lead to serious complications like renal failure, thromboembolism, respiratory failure, aspiration pneumonia, and arrhythmia.…”

Beta‐Blocker and Antipsychotic Treatment of Toxicity from So‐called Designer Drugs

“…Additionally, we agree that the first‐generation butyrophenone antipsychotic haloperidol is associated with fewer anticholinergic adverse effects than first‐generation phenothiazine antipsychotics. However, it has been associated with the development of neuroleptic malignant syndrome, which is why, when considering the reports of hyperthermia following designer drug ingestion, we recommend exercising caution when administering neuroleptics in the setting of designer drug toxicity. We agree there is a role for neuroleptics, but they should not be used as a first‐line agent for patients with undifferentiated sympathomimetic toxicity.…”