1. Induce Vomiting
Chances are that you haven't gotten plankton poison directly. Rather, you've eaten some form of seafood that consumed toxic plankton before being caught. It is now passing the love on to you in the form of ciguatera, shellfish poisoning or some similar ailment. If you spot signs of food poisoning within 3 or 4 hours of eating fish, you should induce vomiting to get the bad food out of you. Sticking a finger down your throat is the best way in these cases--doctors do not recommend taking ipecac syrup because it increases the risk of dehydration.
2. Hydrate
Plankton poisoning tends to involve a lot of vomiting and diarrhea. The biggest danger from those symptoms is dehydration, since water and electrolytes are rapidly depleted from your system. Drink a lot of clear liquids while you are recovering. Water, clear fruit juices and sports drinks like Gatorade are best. Take small and frequent sips rather than great swallows. You need to be able to keep the fluids down. If fruit juices or sports drinks are too sweet to be tolerated, you can dilute them with water. Suck on chips of ice if you can't keep any fluids down, and stay away from alcohol and caffeinated beverages, because they will dry your body out.
3. Take Activated Charcoal
Activated charcoal is used to neutralize poisons in your system, and it can be effective for plankton-produced food poisoning. It bonds with poisons in your digestive system, which prevents your body from absorbing them. You then pass the poison safely out of your body in your stool. Activated charcoal works best if taken within a few hours of the plankton poisoning. It is easy to use and can be purchased over the counter.
4. Eat Mild Foods
You may have considerable difficulty keeping food down in the early stages of plankton poisoning. As you start to feel better, take in nourishment with bland and easy-to-digest food. Soda crackers, applesauce and white rice are often recommended. Stay away from any more fish, and avoid high-fiber foods that may be tough on your digestive system.
5. Take Medication
Your doctor may have specific medication that you can take to alleviate the symptoms of plankton poisoning. There's no anti-toxin for it, but anti-emetics can cut down on nausea, and anti-diarrhea medicine will keep you from running to the bathroom every few minutes. If you're suffering from itching or outbreaks on your skin, a doctor may suggest taking antihistamines. Most of these medications are available over the counter, but check with a medical professional before you take them. They may not be right for your condition.
