Scopolamine
The most effective preventative for motion sickness, transdermal scopolamine, is now back on the market. Here are some products listed:
Allscrips Transderm-Scop 1.5mg/72hr
Cheshire Drugs Transderm-Scop 1.5mg/72hr
Ciba Pharm. Co. Transderm-Scop 1.5mg/72hr
Novartis Consum Transderm-Scop 1.5mg/72hr
Pharmedix Transderm-Scop 1.5mg/72hr .

Side effects of scopolamine

Scopolamine must be used with caution in people with glaucoma and benign prostatic hypertrophy and can cause hallucinations, confusion, disorientation and memory disturbance.

Other drugs

Other less effective drugs include combinations of antihistamines and dextroamphetamine, Dilantin, nifedipine and ginger root. Use of dextroamphetamine is to counter the sedative effect of phenergan with which it is used in combination. Some believe this the BEST “mal de mer” medication.

Single component drugs
Buclizine Hcl (Oral )
Cyclizine Hcl (Oral )
Meclizine Hcl (Oral )
Meclizine Hcl (Rectal )
Promethazine Hcl (Rectal )
Scopolamine Methylbromide (Oral )
Scopolamine Hydrobromide (Transdermal )

The use of the wrist band has been found to be useless in at least one good study, but many swear by it and the “placebo” effect of a doctors recommendation sometimes works wonders. The FDA has approved it’s use for motion sickness – but it is not water proof and this would appear to make it relatively useless to divers.
Or, buy or make seasickness bands. They are merely elastic straps you wear around the wrists which press an acupressure point that is supposedly marvelously effective in preventing motion sickness.

Other Remedies
Try to sit amidships on the water, view the horizon, lean back against a firm surface and avoid neck movement. Try to suit up as quickly as possible and be the first in the water. The effects of motion gradually tend to wear off as time passes on the boat.

nevasic

nevasic is the programme that has been researched by the MRC Spatial Disorientation Group, Imperial College School of Medicine, London, United Kingdom using the branded name “TravelWell”. Their published report – printed in the American Journal of Travel Medicine with results listed in the American National Library of Medicine concludes the programme “provided significant protection against motion sickness”.
nevasic is also the core programme that the National Health Service in the UK researched with pregnant women (under the branded name MorningWell) – the results proving an over 90% success rate in reducing or alleviating the symptoms of nausea and vomiting in pregnancy or “morning sickness”.

Ginger

About 1 gram of powdered ginger has been shown effective against motion sickness in double-blind studies. In Germany, up to 4 grams per day is recommended.

Start dosing the night before a dive; the beauty of the ginger is it’s easy to obtain and had no side effects. You might try gingersnap cookies instead. Ginger root works just as well as the tablets or powder. Ginger ale can also be used. Japanese food marts sell pickled ginger slices that can be used for the same purpose. Ginger: Non-toxic Anti-Emetic

Botanical Name: Zingiber officinale

Plant Part Used: The rhizome

Active Constituents: The dried rhizome contains approximately 1 to 4% volatile oils. The aromatic principles include the sesquiterpene hydrocarbons zingiberene and bisabolene. The pungent principles include the gingerols and shogaols.

Actions on the Digestive System: Classified as an aromatic bitter, ginger stimulates digestion. It is also noted for improving gastrointestinal motility.

1. Ginger also improves the production and secretion of bile from the liver and gallbladder.

2. Ginger also qualifies as a carminative herb. Animal studies in Saudi Arabia show that ginger protects the stomach from the damaging effect of nonsteroidal anti-inflammatory drugs (ibuprofen is an example) and alcohol.

3. Ginger is a noted anti-emetic. While most research has suggested that this action is centered in the GI tract in humans, recent animal studies suggest that there may be some action on the central nervous system also.

4. Health Care Applications Motion Sickness: Ginger has been widely studied as a treatment for motion sickness. A 1982 study found that ginger was superior to dimenhydrinate for reducing motion sickness (caused by rotating a chair). The dose of ginger was 940 mg and it was consumed 20 to 25 minutes before the test

5. A handful of studies since have both agreed and disagreed with these results. One study tested ginger against seasickness in eighty Danish naval cadets unaccustomed to sailing in heavy seas. One gram of ginger reduced vomiting and cold sweating. Fewer symptoms of nausea and vertigo were also reported.

6. A study completed at Louisiana State University with a grant from NASA is more skeptical. Because motion sickness is common in astronauts, the researchers compared the anti-motion sickness activity of ginger and scopolamine (commonly used as a topical patch to treat motion sickness). Using the rotating chair test, they found that scopolamine was effective in reducing motion sickness while one gram of either fresh or dried ginger was not.

7. However, during their discussion of the study, the authors note that the ginger group did have a noticeable reduction in the incidence of vomiting and sweating but not nausea and vertigo.

Honey

You might also like to try a spoonful or two of honey (take creamed honey when traveling, as the runny stuff gets everywhere).

Phenytoin (Dilantin)

Several divers have written about the effectiveness of Epanutin (TM), a brand of phenytoin, (Dilantin in the US). This drug is used and approved for the control of seizure activity. Dosage has not been developed for the medication to be used for seasickness – although reports from divers indicate that it be taken the night before the dive. (South Africa).

There have been several studies where a single dose of phenytoin [200 mg] was given to volunteers who where then spun around. It seems there was a significant decrease in incidents of nausea in those subjects that were given the phenytoin. It seems that it acts on the nervous system of the digestive tract to decrease nervous activity associated with nausea. That was the good news, here the is bad news:

1. Phenytoin is a prescription drug here in the United States, you can’t just drop by the local pharmacy and pick some up.

2. It has some side effects that would be adverse to scuba diving should they occur at depth. These include ataxia, slurred speech, blurred vision, nystagmus, mental confusion, hallucination, headache and dizziness. Thus, it would be advisable for the diver to have ‘tested’ his/her reaction to the medication before the dive. These side effects may not show with just a single dose, but the actions of this drug combined with the effects of nitrogen narcosis need to be considered.

3. There are many drug interactions with phenytoin. Taking this drug while using other medications may produce the side effects that I mentioned above.

In the U.S. its trade name is Dilantin. However, this drug is approved for epilepsy and not for sea sickness.

Stugeron (cinnarizine) is an antihistamine, as is dimenhydrinate (Dramamine), diphenhydramine (Benadryl), meclizine (Bonine, and Dramamine II), and promethazine (Phenergan), (though this last is also a phenothiazine, centrally acting antiemetic)

Stugeron – originally developed for use in the treatment of Parkinson’s disease . Is said to work very well for most people with fewer side effects than scopolamine , et al.

Stugeron (Janssen) – cinnarizine is an antihistamine prescribed for motion sickness – 30 mg before travel then 15 mg every 8 hrs.
*Cinnarizine is not free of central activity over the usual therapeutic dose range of 15 to 30 mg. It is contraindicated for motion sickness in aircrew involved in the control of aircraft. Caution should be exercised in the use of the drug by other aircrew who may be involved in tasks which demand continued attention. This admonition would most likely also apply to it’s use in divers.

Another highly touted treatment is Emetrol, an inexpensive and readily available remedy (OTC in the US) with few side effects. This is a syrupy concoction containing levulose and I can find no studies that show it is beneficial for motion sickness. However, it is non-sedating and has been used by divers prone to seasickness with good effect. It should not be used by those with diabetes or hereditary levulose intolerance.

Dramamine [dimenhydrinate] is not recommended for divers. There is one very good study done in 2000 at the University of Pittsburgh that has shown that it has adverse effects on the ability of divers to trail-make and caused lowered scores on verbal memory tests with depth. “Non-drowsy” Dramamine contains meclizine rather than dimenhydrinate.