Diagnostic Considerations

Although organophosphate toxicity results in decreased cholinesterase, falsely depressed levels of red blood cell cholinesterase can be found in the following cases:

Pernicious anemia
Hemoglobinopathies
Use of antimalarial drugs
Blood collection tubes containing oxalate

Falsely depressed levels of plasma cholinesterase are observed in the following cases:

Liver dysfunction
Low-protein conditions
Neoplasia
Hypersensitivity reactions
Use of certain drugs (eg, succinylcholine, codeine, morphine)
Pregnancy
Genetic deficiencies

Other problems to be considered in the differential diagnosis of organophosphate toxicity include the following:

Carbamate toxicity
Nicotine toxicity
Carbachol toxicity
Methacholine toxicity
Arecoline toxicity
Bethanechol toxicity
Pilocarpine toxicity
Pyridostigmine toxicity
Neostigmine toxicity
Mushroom poisoning ( Clitocybe, Inocybe)
Poison hemlock ( Conium maculatum)poisoning
Myasthenia gravis
Eaton-Lambert syndrome
Guillain-Barré syndrome
Botulism
Eclampsia

Differential Diagnoses

Toxicity, Mushroom
Viral Gastroenteritis

Workup

Bouvier G, Seta N, Vigouroux-Villard A, Blanchard O, Momas I. Insecticide urinary metabolites in nonoccupationally exposed populations. J Toxicol Environ Health B Crit Rev. 2005 Nov-Dec. 8(6):485-512. [QxMD MEDLINE Link].
Boobis AR, Ossendorp BC, Banasiak U, Hamey PY, Sebestyen I, Moretto A. Cumulative risk assessment of pesticide residues in food. Toxicol Lett. 2008 Aug 15. 180(2):137-50. [QxMD MEDLINE Link].
Borger J. Syrian chemical attack used sarin and was worst in 25 years, says UN. The Guardian. September 17, 2013. Available at http://www.theguardian.com/world/2013/sep/16/syrian-chemical-attack-sarin-says-un.
Muñoz-Quezada MT, Lucero BA, Iglesias VP, Muñoz MP, Cornejo CA, Achu E, et al. Chronic exposure to organophosphate (OP) pesticides and neuropsychological functioning in farm workers: a review. Int J Occup Environ Health. 2016 Apr 29. 1-12. [QxMD MEDLINE Link].
Yurumez Y, Durukan P, Yavuz Y, et al. Acute organophosphate poisoning in university hospital emergency room patients. Intern Med. 2007. 46(13):965-9. [QxMD MEDLINE Link].
Gummin DD, Mowry JB, Beuhler MC, Spyker DA, Brooks DE, Dibert KW, et al. 2019 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 37th Annual Report. Clin Toxicol (Phila). 2020 Dec. 58 (12):1360-1541. [QxMD MEDLINE Link]. [Full Text].
Corriols M, Marin J, Berroteran J, Lozano LM, Lundberg I, Thorn A. The Nicaraguan Pesticide Poisoning Register: constant underreporting. Int J Health Serv. 2008. 38(4):773-87. [QxMD MEDLINE Link].
Yamashita M, Yamashita M, Tanaka J, Ando Y. Human mortality in organophosphate poisonings. Vet Hum Toxicol. 1997 Apr. 39(2):84-5. [QxMD MEDLINE Link].
Abdel Rasoul GM, Abou Salem ME, Mechael AA, Hendy OM, Rohlman DS, Ismail AA. Effects of occupational pesticide exposure on children applying pesticides. Neurotoxicology. 2008 Sep. 29(5):833-8. [QxMD MEDLINE Link].
Levy-Khademi F, Tenenbaum AN, Wexler ID, Amitai Y. Unintentional organophosphate intoxication in children. Pediatr Emerg Care. 2007 Oct. 23(10):716-8. [QxMD MEDLINE Link].
Jayawardane P, Dawson AH, Weerasinghe V, Karalliedde L, Buckley NA, Senanayake N. The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka. PLoS Med. 2008 Jul 15. 5(7):e147. [QxMD MEDLINE Link].
Moretto A. Experimental and clinical toxicology of anticholinesterase agents. Toxicol Lett. 1998 Dec 28. 102-103:509-13. [QxMD MEDLINE Link].
Rajapakse BN, Thiermann H, Eyer P, Worek F, Bowe SJ, Dawson AH, et al. Evaluation of the Test-mate ChE (cholinesterase) field kit in acute organophosphorus poisoning. Ann Emerg Med. 2011 Dec. 58(6):559-564.e6. [QxMD MEDLINE Link].
Cha YS, Kim H, Go J, Kim TH, Kim OH, Cha KC, et al. Features of myocardial injury in severe organophosphate poisoning. Clin Toxicol (Phila). 2014 Sep. 52(8):873-9. [QxMD MEDLINE Link].
Liu JH, Chou CY, Liu YL, et al. Acid-base interpretation can be the predictor of outcome among patients with acute organophosphate poisoning before hospitalization. Am J Emerg Med. 2008 Jan. 26(1):24-30. [QxMD MEDLINE Link].
de Silva HJ, Wijewickrema R, Senanayake N. Does pralidoxime affect outcome of management in acute organophosphorus poisoning?. Lancet. 1992 May 9. 339(8802):1136-8. [QxMD MEDLINE Link].
Pawar KS, Bhoite RR, Pillay CP, Chavan SC, Malshikare DS, Garad SG. Continuous pralidoxime infusion versus repeated bolus injection to treat organophosphorus pesticide poisoning: a randomised controlled trial. Lancet. 2006 Dec 16. 368(9553):2136-41. [QxMD MEDLINE Link].
Peter JV, Moran JL, Graham P. Oxime therapy and outcomes in human organophosphate poisoning: an evaluation using meta-analytic techniques. Crit Care Med. 2006 Feb. 34(2):502-10. [QxMD MEDLINE Link].
Eisenkraft A, Gilat E, Chapman S, Baranes S, Egoz I, Levy A. Efficacy of the bone injection gun in the treatment of organophosphate poisoning. Biopharm Drug Dispos. 2007 Apr. 28(3):145-50. [QxMD MEDLINE Link].
Murray DB, Eddleston M, Thomas S, Jefferson RD, Thompson A, Dunn M, et al. Rapid and complete bioavailability of antidotes for organophosphorus nerve agent and cyanide poisoning in minipigs after intraosseous administration. Ann Emerg Med. 2012 Oct. 60(4):424-30. [QxMD MEDLINE Link].
Geller RJ, Lopez GP, Cutler S, Lin D, Bachman GF, Gorman SE. Atropine availability as an antidote for nerve agent casualties: validated rapid reformulation of high-concentration atropine from bulk powder. Ann Emerg Med. 2003 Apr. 41(4):453-6. [QxMD MEDLINE Link].
Rajpal S, Ali R, Bhatnagar A, Bhandari SK, Mittal G. Clinical and bioavailability studies of sublingually administered atropine sulfate. Am J Emerg Med. 2010 Feb. 28(2):143-50. [QxMD MEDLINE Link].
Yavuz, Y, Yurumez Y, Ciftci J et al. Effect of diphenhydramine on myocardial injury caused by organophosphate poisoning. Clin Tox. 2007. 46:67-70.
Pajoumand A, Shadnia S, Rezaie A, Abdi M, Abdollahi M. Benefits of magnesium sulfate in the management of acute human poisoning by organophosphorus insecticides. Hum Exp Toxicol. 2004 Dec. 23(12):565-9. [QxMD MEDLINE Link].
Basher A, Rahman SH, Ghose A, Arif SM, Faiz MA, Dawson AH. Phase II study of magnesium sulfate in acute organophosphate pesticide poisoning. Clin Toxicol (Phila). 2013 Jan. 51(1):35-40. [QxMD MEDLINE Link].
Peter JV, Cherian AM. Organic insecticides. Anaesth Intensive Care. 2000 Feb. 28(1):11-21. [QxMD MEDLINE Link].
Weissman BA, Raveh L. Therapy against organophosphate poisoning: the importance of anticholinergic drugs with antiglutamatergic properties. Toxicol Appl Pharmacol. 2008 Oct 15. 232(2):351-8. [QxMD MEDLINE Link].
Lewine JD, Weber W, Gigliotti A, McDonald JD, Doyle-Eisele M, Bangera N, et al. Addition of ketamine to standard-of-care countermeasures for acute organophosphate poisoning improves neurobiological outcomes. Neurotoxicology. 2018 Aug 30. 69:37-46. [QxMD MEDLINE Link].
London L, Myers JE. Use of a crop and job specific exposure matrix for retrospective assessment of long-term exposure in studies of chronic neurotoxic effects of agrichemicals. Occup Environ Med. 1998 Mar. 55(3):194-201. [QxMD MEDLINE Link].
Tang W, Ruan F, Chen Q, Chen S, Shao X, Gao J, et al. Independent Prognostic Factors for Acute Organophosphorus Pesticide Poisoning. Respir Care. 2016 Apr 5. [QxMD MEDLINE Link].
Raveh L, Eisenkraft A, Weissman BA. Caramiphen edisylate: An optimal antidote against organophosphate poisoning. Toxicology. 2014 Sep 6. 325C:115-124. [QxMD MEDLINE Link].

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Author

Kenneth D Katz, MD, FAAEM, ABMT Assistant Professor, Division of Medical Toxicology, Department of Emergency Medicine, University of Pittsburgh Medical Center; Medical Director, Pittsburgh Poison Center

Kenneth D Katz, MD, FAAEM, ABMT is a member of the following medical societies: American Academy of Emergency Medicine, American College of Medical Toxicology

Disclosure: Nothing to disclose.

Coauthor(s)

Daniel E Brooks, MD Co-Medical Director, Banner Good Samaritan Poison and Drug Information Center, Department of Medical Toxicology, Banner Good Samaritan Medical Center

Daniel E Brooks, MD is a member of the following medical societies: American Academy of Clinical Toxicology, American College of Emergency Physicians, American College of Medical Toxicology

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

Sage W Wiener, MD Assistant Professor, Department of Emergency Medicine, State University of New York Downstate Medical Center; Director of Medical Toxicology, Department of Emergency Medicine, Kings County Hospital Center

Sage W Wiener, MD is a member of the following medical societies: American Academy of Clinical Toxicology, American Academy of Emergency Medicine, American College of Medical Toxicology, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Additional Contributors

Lisa Kirkland, MD, FACP, FCCM, MSHA Assistant Professor, Department of Internal Medicine, Division of Hospital Medicine, Mayo Clinic; Chair, Department of Critical Care, ANW Intensivists, Abbott Northwestern Hospital

Lisa Kirkland, MD, FACP, FCCM, MSHA is a member of the following medical societies: American College of Physicians, Society of Critical Care Medicine, Society of Hospital Medicine

Disclosure: Nothing to disclose.

Acknowledgements

The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous authors Marina C Furtado, MD, and Lisa Chan, MD, FACEP, to the development and writing of this article.

Organophosphate Toxicity Differential Diagnoses

Diagnostic Considerations

Differential Diagnoses

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