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CBRNE - Ricin: Treatment & Medication
Updated: Feb 14, 2008
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Treatment
Prehospital Care
Strictly adhere to universal precautions at all times, although secondary dermal absorption to prehospital providers is not expected. The risk of secondary aerosolization is minimal. Use protective masks, which are effective in preventing toxicity, when an overt aerosol attack is suspected.
Emergency Department Care
- Management
- ED management begins with universal precautions and the ABCs. Add a "D" for decontamination (including the removal of garments). If ingestion is possible, based on the history and presenting findings, consider gut decontamination as well.
- Management also involves the ability to recognize, diagnose, and treat a possible biological event.
- Decontamination
- Decontamination begins by removing garments and cleaning with soap and water.
- If available, use a 0.5% sodium hypochlorite solution with a contact time of 15 minutes. Do not instill this solution into open abdominal, brain, or spinal cord injuries or into the eyes. It can be instilled into noncavity wounds and then removed via suction into disposable containers. This discarded solution is neutralized and nonhazardous in 5 minutes. To make a 0.5% sodium hypochlorite solution, mix 1 part bleach and 9 parts water. Make it fresh daily with a pH in the alkaline range. In the absence of this solution, copious amounts of soap and water may be used.
- Diagnosis
- Diagnosis of an aerosolized attack or food and water contaminant with ricin is similar to that of any of the biological or chemical agents that serve as WMDs. It primarily depends on the clinical and epidemiologic setting. In cases of isolated injection, the diagnosis is extremely difficult.
- The clinical presentation of acute lung injury in a large number of patients in a particular area should suggest a pulmonary irritant. The clinical presentation of severe gastroenteritis or hemorrhagic gastroenteritis in a large number of patients in a particular area should suggest a food and water contaminant.
- Include ricin and other agents (eg, staphylococcal enterotoxin B, Q fever, tularemia, pneumonic plague, inhalational anthrax, chemical agents such as phosgene) in the differential diagnosis.
- Ricin is expected to progress despite antibiotic therapy. Chest radiograph exhibits no evidence of mediastinitis, as would be expected with pulmonary anthrax.
- Staphylococcal enterotoxin B does not progress to a life-threatening syndrome, and phosgene produces ARDS, which is mediated by exertion. Phosgene also has the characteristic odor of newly mown hay or grass and is quite irritating to mucous membranes in lethal amounts.
- Diagnostic testing: Diagnostic testing is of limited value (see Workup).
- Treatment
- Treatment and toxicity depend on the route of exposure. Treatment is supportive, and no antidote is available for ricin.
- Emergency department employees should obey strict universal precautions at all times.
- For dermal exposure, a weak sodium hypochlorite solution (0.1%) and/or soap and water suffice to decontaminate the skin.
- For GI exposure, include gastric decontamination with superactivated charcoal, volume replacement, and H2 blockers in treatment. Include chemistry panels, complete blood count, liver function panel, BUN and creatinine, urinalysis, and type and screen in the laboratory evaluation.
- For percutaneous exposure, base treatment on excision of the injection site, if possible, within the shortest amount of time. Obtain baseline laboratory information, including arterial blood gas and fibrinogen. Although antibiotics serve no role in the treatment of ricin, withholding such therapy in an acutely septic-appearing patient would be difficult. Antibiotics may serve to prevent infection resulting from the percutaneous mechanism. Update tetanus immunization status if unknown.
- For aerosol or pulmonary exposure, provide standard critical care treatment directed toward acute lung injury and pulmonary edema. Maintain a low threshold to secure the patient's airway and ensure adequate oxygenation and ventilation. Obtain a chest radiograph, which may show infiltrates. The clinical course progresses despite antibiotic therapy.
- The only effective treatment for ricin toxicity is prevention. Current investigations are underway with candidate vaccines and ricin inhibitors as antidotes or to facilitate immunotoxin treatment. Pteroic acid, neopterin, pterin tautomer, and guanine tautomer are particularly useful.
- Disposition: Admit and monitor any symptomatic patient and perform aggressive volume resuscitation.
Consultations
Surgical consultation for local excision and removal is warranted for parenteral exposures when a retained foreign body is located.
Medication
Update tetanus status if unknown. If exposure is via parenteral route, antibiotics may be helpful in preventing secondary bacterial infection.
Antibiotics
With regard to ricin toxicity, the only possible indication for antibiotics is for the parenteral mechanism of exposure. Direct the choice of antibiotic to cover skin flora.
Cefazolin (Ancef)
First-generation semisynthetic cephalosporin that arrests bacterial cell wall synthesis, inhibiting bacterial growth.
Adult
1-2 g IV/IM q6-8h
Pediatric
25-50 mg/kg/d IV/IM divided q6-8h
Probenecid prolongs effect of cefazolin; coadministration with aminoglycosides may increase renal toxicity; may yield false-positive urine-dip test for glucose
Documented hypersensitivity; relative contraindication for patients who have a true anaphylactic reaction to penicillin-type agents; cross-reaction is reportedly 3-8%
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal impairment; superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy
Vasopressor agents
Perform adequate volume resuscitation of patients with isotonic fluids and packed red blood cells prior to using or in conjunction with these agents; do not use in place of volume resuscitation. Choice of agent usually is determined by physician preference.
Dopamine (Intropin)
Probably most well-known and used pressor agent. Standard mixture of 200 mg in 250 cm3 produces a concentration of 800 mcg/cm3; administer IV.
Adult
Low dose: 0.5-5 mcg/kg/min IV
Medium dose: 5-10 mcg/kg/min IV
High dose: >10 mcg/kg/min IV
Pediatric
Administer as in adults
Phenytoin, alpha- and beta-adrenergic blockers, general anesthesia, and MAOIs increase and prolong effects of dopamine
Documented hypersensitivity; relative contraindications are tachycardia and myocardial ischemia; increases myocardial demand and oxygen consumption; reportedly causes sudden cardiac death in conjunction with Dilantin (diphenylhydantoin); incidence is rare and never was studied adequately; should not deter use
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Closely monitor urine flow, cardiac output, pulmonary wedge pressure, and blood pressure during infusion; prior to infusion, correct hypovolemia with either whole blood or plasma, as indicated; monitoring central venous pressure or left ventricular filling pressure may be helpful in detecting and treating hypovolemia
Norepinephrine (Levophed)
Often a second-line agent but can be used as a first-line agent; can be used with dopamine. Standard mixture of 4 mg in 250 cm3 produces a concentration of 16 mcg/cm3; administer IV.
Adult
2-4 mcg/min IV; can be increased by 2-4 mcg/min q5-10min prn
Pediatric
Administer as in adults
Effects increase when administered concurrently with TCAs, MAOIs, antihistamines, guanethidine, methyldopa, and ergot alkaloids; atropine may block reflex tachycardia caused by norepinephrine and enhances pressor response
Documented hypersensitivity; relative contraindications are tachycardia and myocardial ischemia; increases myocardial demand and oxygen consumption
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Correct blood-volume depletion, if possible, before giving norepinephrine therapy; extravasation may cause severe tissue necrosis and thus should be administered into a large vein; caution in occlusive vascular disease
Toxoids
These agents are used to induce active immunity. Update tetanus status if unknown.
Diphtheria and tetanus toxoid (Decavac)
Used to induce active immunity against tetanus in selected patients.
Adult
0.5 mL IM
Pediatric
<7 years: Not recommended
>7 years: Administer as in adults
Patients receiving immunosuppressants, including corticosteroids or radiation therapy, may remain susceptible despite immunization due to poor immune response; cimetidine may enhance or augment delayed-hypersensitivity responses to skin-test antigens; avoid concurrent use of medication with systemic chloramphenicol since may impair amnestic response to tetanus toxoid; concurrent use of tetanus immune globulin may delay development of active immunity by several days (interaction is nevertheless clinically insignificant and does not preclude concurrent use)
Documented hypersensitivity; a history of any type of neurologic symptoms or signs following administration of this product; FDA recommends that elective tetanus immunization be deferred during any outbreak of poliomyelitis because tetanus toxoid injections are an important cause of provocative poliomyelitis
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Do not use to treat actual tetanus infections or for immediate prophylaxis of unimmunized individuals (use instead tetanus antitoxin, preferably human tetanus immune globulin); diminished antibody response to active immunization may be seen in patients receiving immunosuppressive therapy; better to defer primary diphtheria immunization until immunosuppressive therapy discontinued; routine immunization of symptomatic and asymptomatic HIV-infected persons is recommended
H2 blockers
Reversible competitive blockers of histamine at H2 receptors, particularly those in the gastric parietal cells where they inhibit acid secretion. The H2 antagonists are highly selective, do not affect H1 receptors, and are not anticholinergic agents.
Famotidine (Pepcid)
Competitively inhibits histamine at H2 receptor of gastric parietal cells, resulting in reduced gastric acid secretion, gastric volume, and reduced hydrogen concentrations.
Adult
Normal renal function: 20 mg IV q12h
Renal failure: 20 mg IV qd
Pediatric
Normal renal function: 0.5 mg/kg IV q12h
Renal failure: No standard recommendations; consider decreasing dose to 0.5 mg/kg IV qd
May decrease effects of ketoconazole and itraconazole
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
If changes in renal function occur during therapy, consider adjusting dose or discontinuing treatment
Antidotes
Used to inhibit or reduce absorption of the toxin.
Activated charcoal (Liqui-Char, Actidose Aqua)
Emergency treatment in poisoning caused by drugs and chemicals. Network of pores present in activated charcoal adsorbs 100-1000 mg of drug per gram of charcoal. Does not dissolve in water. For maximum effect, administer within 30 min after ingesting poison.
Adult
25-100 g PO, 1 g/kg PO, or 10 times weight of ingested poison; give as susp in 4-8 oz of water
Pediatric
<1 year: Not recommended
>1 year: Administer as in adults
May inactivate ipecac syrup if used concomitantly; effectiveness of other medications decreases with coadministration; do not mix charcoal with sherbet, milk, or ice cream (decreases adsorptive properties of activated charcoal)
Documented hypersensitivity; poisoning or overdosage of mineral acids and alkalies
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Not very effective in poisonings of ethanol, methanol, and iron salts; induce emesis before giving activated charcoal; after emesis with ipecac syrup, patient may not tolerate activated charcoal for 1-2 h; can administer in early stages of gastric lavage; without sorbitol gastric lavage, returns are black
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| Overview: CBRNE - Ricin |
| Differential Diagnoses & Workup: CBRNE - Ricin |
 Treatment & Medication: CBRNE - Ricin |
| Follow-up: CBRNE - Ricin |
| Multimedia: CBRNE - Ricin |
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References
CDC and Public Health Training Network. Recognition, Management and Surveillance of Ricin-Associated Illness [Web cast script]. December 30, 2003. [Full Text].
CNN.com. Timeline: UK ricin terror probe. January 23, 2003. [Full Text].
Balint GA. Ricin: the toxic protein of castor oil seeds. Toxicology. Mar 1974;2(1):77-102. [Medline].
Challoner KR, McCarron MM. Castor bean intoxication. Ann Emerg Med. Oct 1990;19(10):1177-83. [Medline].
Ellenhorn MJ, Barceloux DG. Ornamental beans. In: Medical Toxicology Diagnosis and Treatment of Human Poisoning. 1988:1225-27.
FBI. Federal Bureau of Investigations Web Page. Available at www.fbi.gov. Accessed 2000.
Franz D, USAMRIID. Defense against toxic weapons. In: US Army Medical Research Material Command. 1997.
Kopferschmitt J, Flesch F, Lugnier A, et al. Acute voluntary intoxication by ricin. Hum Toxicol. Apr 1983;2(2):239-42. [Medline].
Kortepeter MG, Parker GW. Potential biological weapons threats. Emerg Infect Dis. Jul-Aug 1999;5(4):523-7. [Medline].
Meselson M, Guillemin J, Hugh-Jones M, et al. The Sverdlovsk anthrax outbreak of 1979. Science. Nov 18 1994;266(5188):1202-8. [Medline].
Shih RD, Goldfrank LR. Plants. In: Goldfrank's Toxicologic Emergencies. 6th ed. 1998:1254-55.
US Medical Research Institute of Infectious Diseases. Medical Management of Biocasualities Handbook. 1998.
Zilinskas RA. Iraq's biological weapons. The past as future?. JAMA. Aug 6 1997;278(5):418-24. [Medline].
Further Reading
Keywords
Ricinus communis, toxin, agent of biological warfare, weapon of mass destruction, WMD, beans of castor plant, castor beans, food contaminant, water contaminant, hematemesis, bloody diarrhea, melena, food poisoning, hypoxia, cyanosis, labored breathing, tachypnea, tachycardia, progressive respiratory failure, ricin, biological warfare agent, terrorism
