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What is Ricin Poison? Castor Bean Poisoning Symptoms and Antidote

Castor beans are the most common component used to make castor oil. So, what is ricin? Ricin, also known as castor bean poison, refers to the castor oil waste product. 
Depending on the severity of the ricin poisoning event, ricin has the potential to kill its subject within 36-72 hours of exposure. Even a small amount of ricin has the potential to be fatal. Unfortunately, there are neither reliable tests that can confirm ricin exposure nor any vaccines or antidotes.

The signs and symptoms of ricin poisoning depend on both the type of exposure (inhalation, ingestion, injection) and the dosage used. The general consensus is that ingestion is the least lethal route of exposure, and inhalation is the most lethal.

Eating castor beans is the most common route of ricin ingestion. Occasionally, it may be used to contaminate water supplies as well. Signs and symptoms related to ricin ingestion include:

  • Vomiting
  • Diarrhea (with or without blood)
  • Intestinal bleeding
  • Dehydration and hypotension (low blood pressure)
  • Hallucinations
  • Seizures
  • Blood in urine
  • Multi-organ failure 
  • Death

Ricin is not easily absorbed through the skin. However, it can be injected subcutaneously, intramuscularly, or intravenously. Signs and symptoms related to ricin injection include:

  • Fever
  • Tachycardia (rapid heart rate)
  • Tachypnea (rapid respiratory rate)
  • Hypotension
  • Hepatitis, pancreatitis, nephritis (inflammation of the liver, pancreas, kidney)
  • Myocardial damage
  • Cerebral edema
  • Vomiting/diarrhea
  • Bone marrow suppression

Ricin that is administered via inhalation can result in extensive and debilitating symptoms within hours. Signs and symptoms related to ricin inhalation include:

  • Respiratory distress
  • Fever
  • Cough
  • Nausea
  • Diaphoresis (sweating)
  • Pulmonary edema and cyanosis (blue coloring related to lack of oxygen)
  • Hypotension and respiratory failure 
  • Death

Unfortunately, there is no known ricin antidote. For this reason, ricin exposure should be avoided through all means necessary. Should an individual be unable to avoid exposure to ricin, the most important thing that can then be done is to get the ricin poison out of the body as quickly as possible.

Regardless of the type of exposure, all curative actions for ricin poisoning are going to focus on supportive measures, while also eliminating all ricin poison from the body. Specific procedures are case-dependent but will likely include some combination of electrolyte replacement, coagulation corrections, renal function tests, and the monitoring of liver function. Respiratory care and seizure management may also be needed. All individuals with assumed ricin poisoning need to be admitted for medical care.

Intoxication with ricin poison causes a significant immune response. The bodies of poisoned patients will show evidence of ricin antibodies within two weeks of their exposure. A diagnosis of ricin poisoning may be made after clinical analysis of a nasal swab or a sample of bodily fluid. However, this diagnostic testing tool has not been clinically validated, and it is not widely available.

When ricin is ingested, it’s early presence mimics food poisoning. Early ricin symptoms can lead to significant dehydration. Treatment, therefore, usually includes fluid replacement via IV fluids and medications to treat the potential hypotension. If the ricin ingestion is recent, flushing the stomach with activated charcoal to soak up the poison or pumping the stomach may also be helpful, if vomiting hasn’t occurred yet.

Injected ricin has the potential to affect the heart, lungs, liver, pancreas, kidneys, bone marrow, and brain. Patients will need a variety of tests and extensive monitoring. Fluid balance will be critical, as well as stopping extensive inflammation of any organs.

Inhaled ricin often affects multiple people at once, leading to a cluster of people with similar symptoms. These circumstances have the potential to overwhelm a health care facility. Treating inhaled ricin may involve a chest x-ray to determine if there is fluid in the lungs and breathing assistance (intubation or ventilator). IV fluids may be given to rehydrate, but care must be taken to not overwhelm the lungs with extra fluid.

Yes, ricin can kill a person. A small amount, comparable to a grain of table salt, is enough to be lethal. Ricin poisoning alters cell function and causes cell death. Once this occurs, vital organs will cease functioning. Remember, there is no ricin antidote.

Though all who are exposed to ricin poison need medical care, there are some steps to take right away.

  • Call 911.
  • If the ricin has been released via aerosol, get fresh air right away. Leave the building or move away from the area where it was released. You may also need to shelter in place.
  • Remove and/or change your clothing. Cut clothes off to avoid pulling them over your head. Avoid touching contaminated areas (on yourself or others) as much as possible.
  • Wash as quickly as possible with large amounts of soap and water. Rinse your eyes for 10-15 minutes with plain water if they are burning. Do not put contacts back in. Wash any eyeglasses you were wearing.
  • Dispose of your clothes after you have washed yourself. Using gloves, if possible, place your clothes (and contacts) in a plastic bag. Double seal the bag and notify health professionals that you have clothing to dispose of. They will take care of full disposal.
  • If you believe you or someone has ingested ricin, do not drink fluids or induce vomiting. Wait for care from medical professionals.

Ricin is a dangerous and fast-acting potential bioterrorism threat. Any potential ricin exposure should immediately involve poison control, public health officials, law enforcement, and health care workers. The Centers for Disease Control and Prevention categorizes ricin as a Category B agent with moderate to high mortality, and it should be treated as such by all individuals. Failing to treat quickly and appropriately can result in death.








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