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Dantrolene is not the answer to 2,4-dinitrophenol poisoning: more heated debate
  1. Jason Van Schoor1,2,
  2. Esha Khanderia3 and
  3. Andrew Thorniley4
  1. 1 Department of Anaesthetics, North Central School of Anaesthesia, London, UK
  2. 2 Division of Surgery of Surgery and Interventional Science, University College London, London, UK
  3. 3 Division of Surgery, Cancer and Cardiovascular, Imperial College London Department of Surgery and Cancer, London, UK
  4. 4 Department of Anaesthetics and Intensive Care, Hillingdon Hospitals NHS Foundation Trust, Uxbridge, Greater London, UK
  1. Correspondence to Dr Jason Van Schoor, jasonvanschoor{at}


There has been a resurgence in the use of 2,4-dinitrophenol, C6H4N2O5 (DNP) recently as an illegal weight loss drug. We present a case of a healthy 25-year-old girl who took two tablets of DNP, purchased from an overseas online retailer. She was managed with aggressive, invasive cooling measures and 2.5 mg kg–1 dantrolene. Despite this, her temperature continued to rise exponentially to 41.5°C. Cardiac arrest occurred and resuscitation was unsuccessful. To our knowledge, this is the first reported case of the ineffective use of dantrolene in acute DNP poisoning. We review the pathophysiology of DNP toxicity and argue that the use of dantrolene therapy is biochemically implausible, based on poor evidence and likely to be futile. We have contacted the UK National Poisons Information Service (NPIS/TOXBASE) to propose changes to the management of acute DNP toxicity.

  • pharmacology and therapeutics
  • safety
  • toxicology
  • unwanted effects / adverse reactions
  • adult intensive care

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  • Patient consent for publication Next of kin obtained.

  • Contributors The article had contributions from all three authors who were also involved in the management of this case in intensive care. The case report was written from the information in the patient’s notes after obtaining written consent from the patient’s next-of-kin. The literature review was done by searching PubMed for relevant articles. JVS is the first author and guarantor of the article.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests JVS is a ST4 Registrar in Anaesthetics and Intensive Care Medicine, North Central School of Anaesthetics, London and an Anaesthetic Academic Clinical Fellow who holds an Honorary Research Assistant post in the Division of Surgery and Interventional Science University College London. EK is a CT2 in General Surgery in the North West Thames Deanery. She has undertaken a rotation in Intensive Care Medicine as part of her surgical training. AT is a consultant in Anaesthetics and Intensive Care Medicine at The Hillingdon Hospitals NHS Trust.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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