Shellfish Toxicity Treatment & Management

Updated: May 11, 2022
  • Author: Thomas C Arnold, MD, FAAEM, FACMT; Chief Editor: Asim Tarabar, MD  more...
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Emergency Department Care

Therapy for all shellfish poisonings is supportive and symptom-driven. Support and maintenance of the airway are of crucial importance in paralytic shellfish poisoning.

Gastrointestinal decontamination with activated charcoal is recommended for patients who present within 4 hours of ingestion. Nasogastric or orogastric lavage may be performed if the patient presents within 1 hour of ingestion, but this is often unnecessary.

If gastric lavage is performed, the use of isotonic sodium bicarbonate solution as a lavage irrigant has been suggested because many of the shellfish toxins have reduced potency in an alkaline environment.

Okadaic acid undergoes enterohepatic recycling that could be interrupted by delayed or repeat charcoal administration.

The greatest danger is respiratory paralysis. Close monitoring for at least 24 hours and aggressive airway management at any sign of respiratory compromise should prevent severe morbidity and mortality.

Neostigmine and edrophonium have been used to improve muscle weakness following tetrodotoxin intoxication, which is similar to saxitoxin intoxication. Nonetheless, no clinical trials have evaluated the use of these drugs for saxitoxin exposures.



Routine surveillance of shellfish beds for known toxins should prevent most forms of shellfish poisoning. Consumption of shellfish harvested outside of regulated areas or during times known to be associated with red tide is dangerous and should be avoided. Check with local health officials before collecting shellfish, and look for advisories about harmful algal blooms or water conditions that may be posted at fishing supply stores, by beach managers, or local health authorities. Harmful algal bloom (HAB) advisories are posted online by many states. [1]

Shellfish sold as bait should never be consumed. Bait products do not need to meet the same food safety regulations as seafood for human consumption. [1]