Common Medications for Motion Sickness

Most over-the-counter (OTC) drugs for prevention of motion sickness are based on antihistamines. They work by depressing the brain's emetic or vomiting center. They are moderately effective and have minimal side effects, including drowsiness and dry mouth.

Drugs based on meclizine (Bonine, Antivert, Dramamine II) cause less drowsiness than the old standard drug, dimenhydrinate (original Dramamine, Triptone, Gravol). Diphenhydramine (Benadryl), an antihistamine also used as a sleeping pill, can cause significant drowsiness.

Using OTC Drugs Effectively

Most dimenhydrinate- and meclizine-based drugs are sold as pills or as chewable tablets. They should betaken at least two hours before boarding so the drug can go through the digestive system and into the bloodstream. A person already nauseous or vomiting will get no benefit because the drug will be expelled in the next bout of vomiting, or will be trapped in the stressed digestive system. OTC drugs are useful for preventing seasickness, but not for curing it.

It is essential to get the drug into your system in a sufficient amount, which varies with a person's size and body chemistry. Some people need to exceed the recommended dose, while others cut it in half. Further, some OTCs lose effectiveness in 4-6 hours. You might want to "test drive"a drug ahead of time (well before you go boating) for effectiveness and side effects.

A second component of drug effectiveness is faith in the drug. Studies show that as much as 40% of all seasickness can be alleviated by the belief that the drug is effective, even if the patient has taken a sugar pill (placebo) instead of the real thing.

Here's Something to Try

Too often people don't think they will get seasick until they get out on the water, and then it's too late to take an OTC drug as a preventative. If you're one of those, here's something you can try. Next time you go out, take along a package of chewable

dimenhydrinate or meclizine tablets. If you find that you're starting to feel sick, take a couple of the tablets and chew but don't swallow. Instead, hold the "mush" under your tongue or against the inside of your cheek, where the drug can be absorbed through the lining of the mouth. Research shows that the drug passes into the bloodstream, although it still takes a couple of hours to reach full strength. Some sufferers report excellent results from this approach.