The emergencies to be treated first during the acute phase of the poisoning are the hemodynamic and hydroelectric disorders likely to lead to a state of shock that can prove fatal in sensitive subjects. The use of large volumes of isotonic solutions and vasopressor amines may then be necessary.

In general, gastrointestinal symptoms are the first to appear.

Diarrhea usually responds well to antisecretory anti-diarrheals like racecadotril (Tiorfan®); vomiting to classical antiemetics and abdominal pains to antispasmodics.

In severe cases, decontamination with activated charcoal (if administered within 3-4h after the poisoning) and a gastric lavage can be applied. However, these methods must be avoided in case of intense vomiting.

In general, these disorders resolve after a few days.

These symptoms are found in most severe cases and are relevant of an exposure to large amounts of toxins. Their occurrence usually requires emergency hospitalization.

Bradycardia and hypotension require IV or IM atropine (0.5 to 1 mg every 5 minutes, if necessary) to maintain a heart rate greater than 60 bpm.

Cardiotonics (Isoprenaline…) can be administered in case of persistent bradycardia, and pralidoxime (Contrathion®…; 200 to 1000 mg, slow infusion) for its cholinesterase reactivator property.

Finally, rehydration is required in the event of severe hypotension.

Mannitol is usually indicated for the treatment of neurological symptoms during the acute phase of CP. The dose of mannitol generally recommended is 0.5 à 1g/kg of body weight over a 30-45 minutes period, administered within 48-72h after the consumption of the toxic fish, for maximum efficiency. However, improvements have been observed, even up to several weeks after intoxication.

Please note: As mannitol causes intracellular dehydration, it should be administered once the patient is correctly rehydrated, especially if one suffer from severe diarrhea or vomiting. In addition, mannitol should be avoided for patients with cardiac failure.

Many hypotheses have been suggested to explain the mechanisms of action of mannitol: its osmotic properties, chelator of free radicals and/or inhibitor of successive depolarizations induced by ciguatoxins.

Although controversial, the use of mannitol in the acute, and chronic, phase is recommended in most studies.

Learn more about Mannitol use in CP-affected patients management:

One of the specificities of Ciguatera lies in the occurrence of "hypersensitivity" to scertain foods and drinks (regardless of the presence of ciguatoxins), even environmental factors (intense physical activity, exposure to the sun, etc.); resulting in the transiant reactivation or accentuation, by peaks of a few hours to a few days, of certain symptoms related to the poisoning (itching, general malaise, muscle pain/weakness, etc.).

In order to limit this phenonemon, it is recommended to follow a specific diet, free of marine products, animal proteins (especially red meats), alcohol, coffee and nuts for a period of one month minimum or until symptoms disappear.

It may be that this "hypersensitivity" to certain foods persists over time (several months, even years). It is therefore recommended to keep a diary of triggering foods and note the nature of reactions associated and their intensity. These foods will need to be avoided for several weeks, then reintroduced one by one.

In some cases, the hypersensitivity can extend to other food products, such as plant-based proteins, high-fat products, dairy products, foods rich in histamines, etc.

The diet must be adapted on a CASE-BY-CASE basis.

This phenomenon will disappear spontaneously with time

To date, the treatments offered by the Western medicine are exclusively palliative, which leads many island populations, particularly in the Pacific region,to turn to traditional medicine.

Ethnobotanical studies carried out in the Pacific region, have made it possible to establish a list of nearly 100 plants used in the composition of traditional remedies intended to treat ciguatera. These plants could contain active principles which, not only would act on symptoms improvement, but would also allow the human body to “detoxify” faster. In any case, this is the hypothesis that appears in the light of the testimonies of local populations and published in vitro studies.

Among these remedies, only the one based on the leaves of Heliotropium foertherianum (Boraginaceae, common name: "Faux tabac" in New Caledonia and "tahinu" or tohonu" in French Polynesia) has been studied until the isolation of its main active compound, the Rosmarinic acid.

Heliotropium foertherianum or "Octopus bush" . a) shrub; b) tree; c) leaves; d) flowers and et burgeons. H. foertherianum preferentially grows by the sea, on the sand. © D. Laurent, C. Gatti et F. Rossi

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How is the traditional remedy based on "Octopus bush" made?

In French Polynesia, this remedy is widely used, especially in the islands where the healthcare access is limited.

Islanders generally take 5 to10 yellow leaves, which they clean and boil in 1 liter of water until the latter is reduced to ½ litre. The decoction thus obtained is drunk hot or cold, in one or several time. According to custom, the consumption of this remedy should not exceed 3 consecutive days.

To be effective, the treatment must be taken as soon as possible. It should also be noted that the effectiveness can vary from one tree to another, insofar as they do not all contain the same concentrations of rosmarinic acid.

The beneficial activity of this remedy has been demonstrated through various pharmacological studies including an in vivo test on mice and various in vitro tests (electrophysiology, neurophysiology, cell physiology and neurotoxicity). These studies showed that this traditional remedy counteracted the toxic effect caused by ciguatoxins.

Rosmarinic acid is one of the main active molecule found in the infusion of H. foertherianum leaves. This phenolic compound which does not show any notable toxicity, and whose antioxidant and anti-inflammatory activities, as well as beneficial properties on the cardiovascular system and some neurodegenerative diseases, can be of great interest in  treatment of ciguatera. A “detoxifying” activity has been observed on neuroblastoma cell cultures and ligand-receptor detection test.

Rosmarinic acid, but also the traditional remedy based on H. foertherianum leaves, could therefore constitute a promising alternative treatment to Ciguatera poisoning.

More information on the protective effect of H. foertherianum against CTXs:

Fanny Rossi, Valérie Jullian, Ralph Pawlowiez, Shilpa Kumar-Roiné, Mohamed Haddad, H. Taiana Darius, Nabila Gaertner-Mazouni, Mireille Chinain, Dominique Laurent (2012). Protective effect of Heliotropium foertherianum (Boraginaceae) folk remedy and its active compound, rosmarinic acid, against a Pacific ciguatoxin. Journal of Ethnopharmacology, Volume 143, Issue 1, Pages 33-40, ISSN 0378-8741, https://doi.org/10.1016/j.jep.2012.05.045.

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Learn more about other traditional remedies used in the South Pacific and French Polynesia to treat Ciguatera:

Laurent Dominique, Bourdy Geneviève, Amade Philippe, Cabalion Pierre, Bourret Dominique. (1993). La gratte ou ciguatera : ses remèdes traditionnels dans le Pacifique Sud. Paris : ORSTOM, 152 p. (Didactiques). ISBN 2-7099-1171-X. ISSN 1142-2580.

Kumar-Roiné, S., Taiana Darius, H., Matsui, M., Fabre, N., Haddad, M., Chinain, M., Pauillac, S. and Laurent, D. (2011), A Review of Traditional Remedies of Ciguatera Fish Poisoning in the Pacific. Phytother. Res., 25: 947-958. https://doi.org/10.1002/ptr.3396

François Chassagne, Jean-François Butaud, Frédéric Torrente, Eric Conte, Raimana Ho, Phila Raharivelomanana, (2022). Polynesian medicine used to treat diarrhea and ciguatera: An ethnobotanical survey in six islands from French Polynesia. Journal of Ethnopharmacology, Volume 292, 115186. https://doi.org/10.1016/j.jep.2022.115186.