In a few weeks I will take a group of divers to Egypt on a live-aboard.
Some people will be prone to seasickness and I am going to advise them to bring some anti-seasickness medication.
However, I am aware of some problems with taking these drugs while diving, like drowsiness and reported nitrogen narcosis in relative shallow depths.
Can you please advise me which anti-seasickness medication is best, i.e. which interferes least with diving?
I will probably need the pharmacological name as well as trade name.

You are absolutely right, sea-sickness can ruin a complete diving trip.
Unfortunately, no medication can completely prevent sea-sickness in all cases, and the absence of side effects is therefore of paramount importance.
To my knowledge, there are only a few safe drugs that are effective for sea-sickness. The best know (at least in Belgium) is a drug made by Janssen Pharmaceuticals by the name of Touristil. It contains 20mg of Cinnarizine (a calcium antagonist that has antihistamine properties) and 15 mg of domperidone, which is an anti-emetic. The anit-kinetosis (anti-seasickness) effect is probably induced by the cinnarizine. Dosis is three pills a day in case of severe sea-sickness sensitivity. You can start with one in the morning, preferaby before really feeling sick (otherwise you throw up the pills) and see how the day goes. Effect is maximal after 1 hour.
Although the drug is usually very well tolerated, it is best to take it the day before (even on the shore) to see if the diver is not unusually sensitive. It may very occasionally cause fatigue and sleepiness. Since seasickness itself causes these same symptoms, it is best to test before.
Recently, an anti-kinetotic effect of Cinnarizine pure (commercial name "Stugeron" also by Janssen) has been shown in a dosis of 3x25mg/day (Melamed et al, Undersea Hyperb Med).
The scopolamine patch often used in the US is not easy to obtain in Europe and is really not recommended.
Other medication is likely to have a central depressing effect (anti-histamines) and may indeed interfere with alertness under water and nitrogen narcosis.
Needless to say that DAN does not recommend diving to narcotic depths for any diver.
An antikinetotic effect has been described with Ginger (Gember) pills at a dose on 700mg x 3 per day, but although this may seem a "harmless" alternative (nature medicine) this has never passed real scientific tests of efficacy, needs to be prepared by a pharmacist and it are really BIG pills to swallow. So I would not recommend it.
When someone is seasick he should not dive !! Nausea and vomiting can seriously interfere with buoyancy and may be the cause of pulmonary barotrauma. Also, if someone is seasick regularly, this may mask the vertiginous symptoms of some forms of decompression sickness, or at least not alert the diver's buddies that there is a problem. We recently treated a diver for inner ear decompression sickness who's transfer had been delayed by 6 hours because "he had been seasick on previous trips". Everybody seemed to forget that the sea was very calm that day, that the seasickness only started a few minutes after surfacing from a deeper dive, and that it did not go away with lying down, eyes closed, nor did it go away for 5 hours after the diver had been on shore again.
It is in most cases illusory to think seasickness will go away once you're in the water.

I have just read a piece that suggests using Emmetrol for sea sickness for divers.
May I have your comments please.



EMMETROL is a commercial product which is apparently an extract of Coca Cola syrup. This is not a medicinal product and will not be found on any medical formulary. It's a special kind of sugar, and apparently this also works very well for nausea in children.


There is, to my knowledge, no medical literature on its use in diving and so no knowledge of the complete list of the contents of the available preperations and their side effects.


Should you suffer from motion sickness and intend to use this product I advise you to proceed with caution as we cannot recommend its use nor its avoidance at this stage.


My advice to you is keep your eyes on the horizon, stay on deck and keep yourself well hydrated with non-alcoholic beverages