A diagnosis of cyclonite poisoning is based on a history of exposure and the presence of typical clinical signs. Blood cyclonite
concentration measurement is not readily available in most clinical settings.
High-performance liquid chromatography can be used to determine plasma concentrations of cyclonite. In five people acutely
exposed to cyclonite, plasma concentrations of cyclonite strongly correlated with clinical and laboratory presentation.8 In veterinary medicine, this analysis is uncommon and finding a laboratory to perform it may be difficult.
If a patient is not exhibiting clinical signs and the exposure is recent, emesis can be induced under veterinary supervision
either with hydrogen peroxide (2.2 ml/kg orally, repeat in 10 to 15 minutes if first attempt is unsuccessful) or apomorphine
(0.03 mg/kg intravenously or 0.25 mg/kg diluted with saline solution and instilled into the conjunctival sac).9 Because of the putty-like consistency of C-4, it may stay in the animal's stomach for hours before signs develop.
Activated charcoal (1 to 3 g/kg orally) can be administered cautiously as aspiration may occur. Cyclonite is not water soluble,
and the aqueous slurry of activated charcoal may have limited benefit.8,10 However, since the absorption of cyclonite is usually delayed, activated charcoal is commonly administered in cyclonite-exposure
There is no specific antidote available for treating cyclonite toxicosis. Treatment is supportive and symptomatic. Close patient
monitoring is necessary as seizures may occur rapidly. Seizures are expected to respond to diazepam (0.5 to 2 mg/kg intravenously).9 If seizures persist, phenobarbital (2 to 5 mg/kg) can be given in addition to diazepam. Intravenous fluid therapy at two
times the maintenance rate with isotonic crystalloid is recommended. Vomiting can be treated with antiemetics: maropitant
(1mg/kg subcutaneously once a day), ondansetron (0.1 to 0.2 mg/kg intravenously b.i.d. to q.i.d.), or metoclopramide (0.2
to 0.5 mg/kg subcutaneously or intravenously t.i.d.).9 Gastrointestinal protectants such as sucralfate (0.25 to 1 g orally t.i.d.) and famotidine (0.5 mg/kg intravenously or subcutaneously
one or two times daily) can be given.9
If serious signs develop, monitor the patient's serum chemistry profile, complete blood count, electrolytes, and acid-base
status. Clinical signs may last for days. Elevated liver enzyme activities have been reported for weeks beyond the resolution
of other signs.6
Hemodialysis has not been shown to reduce C-4 concentrations, shorten the clinical period, or decrease seizure activity.11
The outcome in most cases is expected to be good provided seizures are controlled quickly and no other complications, such
as aspiration, develop. Complete recovery with appropriate medical attention is expected in most cases.
Dr. Irina Meadows
Irina Meadows, DVM, DABT
ASPCA Animal Poison Control Center
1717 S. Philo Road, Suite 36
Urbana, IL 61802
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2. Harrell-Bruder B, Hutchins KL. Seizures caused by ingestion of composition C-4. Ann Emerg Med 1995;26(6):746-748.
3. Agency for Toxic Substances and Disease Registry. Toxicologic profile for RDX. Available at:
http://www.atsdr.cdc.gov/. Accessed April 6, 2013.
4. De Cramer KG, Short RP. Plastic explosive poisoning in dogs. J S Afr Vet Assoc 1992;63:30-31.
5. Woody RC, Kearns GL, Brewster MA, et al. The neurotoxicity of cyclotrimethylenetrinitramine (RDX) in a child: a clinical
and pharmacokinetic evaluation. J Toxicol Clin Toxicol 1986;24:305-319.
6. Bruchim Y, Saragusty J, Weisman A, et al. Cylonite (RDX) intoxication in a police working dog. Vet Rec 2005;157:354-356.
7. AnTox Database. Urbana, Ill: ASPCA Animal Poison Control Center, 2001-2011.
8. Kucukardali Y, Acar HV, Ozkan S, et al. Accidental oral poisoning caused by RDX (cyclonite): a report of 5 cases. J Intensive Care Med 2003;18(1):42-46.
9. Plumb DC. Plumb's veterinary drug handbook. 7th edition. Ames: Iowa State University Press, 2011;77-79, 304-308, 407-409, 624-626, 677-680, 752-753, 805-809, 943-944.
10. Hollander AI, Colbach EM. Composition C-4 induced seizures: a report of five cases. Mil Med 1969;134(13):1529-1530.
11. Fishkin, R.A., Stanley, S.W., Langston, C.E. Toxic effects of cyclonite (C-4) plastic explosive ingestion in a dog. J Vet Emerg Crit Care 2008;18(5):537-540.