Each week we will aim to bring out a concise email that provides 4-5 key pieces of information addressing a specific issue in clinical therapeutics.
This week: Neuroleptic Malignant Syndrome (NMS)
The Neuroleptic Malignant Syndrome (NMS) is a rare but potentially fatal adverse effect associated with antipsychotic medications, with the prevalence estimated at approximately 1 in 10,000 – 20,000 cases. Even though the prevalence of NMS is low, given that antipsychotic drugs are widely prescribed there is a reasonable chance of encountering this syndrome in the residential aged care setting.
- There are four key elements associated with NMS – fever, autonomic instability (significant variability in blood pressure and pulse rate), extrapyramidal symptoms (especially severe muscular rigidity, tremor) and altered mental state (confusion or delirium). NMS is often accompanied by an increased serum concentration of creatinine kinase (CK). Raised white blood cell count, impaired LFTs, renal function impairment, altered coagulation studies and ECG abnormalities have also been reported.
- The clinical presentation of NMS is highly variable, sometimes occurring within hours of the first dose of antipsychotic, or after some months of uneventful treatment. Management involves discontinuing the anti-psychotic, giving IV hydration, DVT prophylaxis and cooling the patient.
- It is estimated that 30% of patients develop NMS again after re-challenge. If ongoing treatment with an antipsychotic is considered necessary, guidelines suggest an approach whereby it is necessary to wait at least 5 days before the re-introduction of the antipsychotic. Using an alternative antipsychotic (preferably structurally unrelated) is advisable. Start treatment with low doses, escalating slowing and with close monitoring.
- Early detection is the most important principles with NMS – the most important survival benefits are derived from prompt discontinuation of the antipsychotic drug and prompt implementation of intensive and appropriate supportive care.
Please consider these issues when preparing RMMR reports or education sessions. Contributions of content or suggested topics are welcome and should be sent directly to email@example.com.