.... of these are dimenhydrinate, a compound that research has shown not to be appropriate for use while diving:
"University Of Pittsburgh researchers find some over-the- counter medicine may affect scuba divers' performance
PITTSBURGH, Aug 30, '00 -- Scuba divers should think twice about taking certain over-the-counter medications before diving, say emergency physicians at the University of Pittsburgh School of Medicine who conducted studies on the effects of Dramamine® and Sudafed® on scuba divers' performance. The results of the studies, published in the September issue of Pharmacotherapy, are among the first to have been conducted in hyperbaric oxygen (HBO) chambers, where pressures experienced by divers at different depths can be simulated accurately.
While most divers know it is ill-advised to take any kind of medication before a dive, many will take Dramamine® to combat the effects of seasickness or take Sudafed® to ease pressure in the sinus and ears. But, the researchers wondered might divers be subjecting themselves to greater risks for decompression sickness and nitrogen narcosis?
Nitrogen narcosis and decompression sickness result from inhaling compressed air. Nitrogen narcosis is attributed to the depth of a dive and occurs when divers become disoriented and, in rare cases, become unconscious. It can be remedied by ascending back to the surface of the water. Decompression sickness is associated with the length of a dive and is caused when nitrogen bubbles arise in the blood, resulting in severe pain. Unlike nitrogen narcosis, decompression sickness can lead to permanent damage. Potential neurologic complications include stroke and
paralysis.
According to the results of their studies, the researchers found Sudafed® to be relatively "safe," but determined that Dramamine® could have serious consequences on a diver's mental functioning and judgment. "Our findings indicate that Sudafed® is unlikely to cause problems for divers. But, Dramamine® should be avoided prior to diving because of its adverse affects on mental agility," says David McD Taylor, M.D., principal investigator of the study, who is now at the Royal Melbourne Hospital, Victoria, Australia.
"Hopefully the results of these studies will make divers more knowledgeable, allowing them to dive safely," says Kevin O'Toole, M.D., F.A.C.E.P., associate professor of emergency medicine, director of the hyperbaric medicine program and co-principal investigator of the study.
In both studies, researchers looked at 30 people recruited from local diving clubs to determine the psychometric and cardiac effects of both drugs. All participants were required to be active scuba divers and had to be at least 18 years old. The study used a double-blind, placebo-controlled, crossover design -- whereby participants eventually received both the placebo and each study drug, but neither the subjects nor the researchers knew which drugs they were taking.
Each participant came for three separate testing sessions at least one week apart. Each session involved the ingestion of the drug or placebo and testing inside the HBO chamber under two simulated diving conditions -- one just under three feet below sea level and the other at 66 feet below sea level, a common depth for recreational diving. While in the simulated diving chamber, all subjects were connected to a cardiac monitor to record both heart rate and cardiac rhythm. A total of seven separate tests were performed to study cognitive and behavioral patterns.
HBO chambers are typically used to treat decompression sickness in divers who get into trouble during ascent back to the water's surface. The HBO facility at UPMC is used primarily for carbon monoxide poisoning, wounds that are not healing, burns and other problems that may be helped by increasing the amount of oxygen delivered to the tissues."
In terms of what you may wish to consider, the following is my oft posted mal de mer spiel. It's an updated version of a piece from my Jan/Feb '00 "Ask RSD" column in "Rodale's Scuba Diving":
"Sea sickness, which shows wide variation in susceptibility among individuals, is not yet fully understood. It is believed to occur when portions of the brain tasked with maintaining balance receive input from the eyes, inner ear, muscles and joints that is inconsistent and unexpected over an extended period of time.
Prevention is a first step. Avoid fatigue and get adequate rest. Eat modestly, avoiding greasy, fatty, acidic and spicy foods. Don't skip breakfast, but stick to bland foods like toast, rolls and cereal. Go easy on tea and coffee, and very, very easy on alcoholic beverages. When on the boat, don't get overheated--stay under a sunshade, don't put on your protective suit until necessary, and get in the water as soon as possible. Search out a spot low and in the center where motion is minimized, face forward, focus your eyes on a fixed object on the horizon or elsewhere, avoid unnecessary neck movements and stay out of exhaust fumes. Do not go below, read anything or look through binoculars. If you must vomit, do so freely, but not anywhere on the boat, and especially not in the marine toilet.
There are plenty of medications available, and you may wish to discuss this with your physician. Among those reported to be the most effective are meclizine and scopolamine. Prescription strength meclizine commonly comes as Antivert. Scopolamine can be delivered through a transdermal patch, Transderm Scop, orally, and as a gel applied to the wrists. The gel reportedly works faster, but not as long as the patch. Scopolamine is the US Navy's first line sea sickness drug, including for divers, and DAN approves it with a trial run. Occasionally Phenergan, whose primary indication is as a sedative, is recommended. It can cause very serious drowsiness, however, and is sometimes prescribed in combination with a stimulant to counteract this. The above drugs are prescription only and have reported side effects, most commonly dryness of the mouth and drowsiness. They may also cause blurred vision, dizziness and even confusion in some users, and it is recommended to carefully discuss their use with your physician, give them a trial run prior to use in conjunction with diving, and take them only according to instructions.
Over the counter (OTC) drugs include Bonine, Dramamine (Not recommended due to demonstrated adverse effects on alertness & performance), Dramamine II (Advertised as a "less drowsy" formula. As this implies, be aware that some individuals still do experience some degree of drowsiness.) and Triptone (Same active ingredient as original Dramamine, dimenhydrinate, so draw your own conclusions) . A British drug, Stugeron (cinnarizine), has been mentioned by several sources as an effective treatment (Have seen a recent research piece suggesting impairment at higher doses), but it is not yet available in the US. Those diving in such places as Mexico & the British Virgin Islands can find it. Many report these OTC medications most effective if taken at bedtime the night prior to diving, with a second dose about an hour before diving, although recommended dosage amounts should of course not be exceeded. These medications often cause significant dryness of the mouth. Stay very well hydrated.
Considering more "natural" remedies, ginger is frequently mentioned, which can be taken in powdered, crystallized or root form (recommended preparations), or as ginger snaps, ginger ale, or tea. As heartburn with the use of ginger has been reported, also pack an antacid. Others swear by wrist straps, such as 'Sea Bands,' usually wooden or plastic balls on elastic bands which are placed so as to exert pressure on an acupressure point on the inside of the wrist. There are also 'artificial-horizon' glasses. Even aromatherapy has been tried, with a combination of mandarin, peppermint, spearmint and lavender oil being recommended.
In the final analysis, you will need to discover what works best for you with the least risk, side effect, cost and inconvenience. If you take any medications, you should understand their adverse effects and carefully follow directions for use. And remember, there is one safe, sure cure: 'Sleep under a tree all day.' "
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such.
Best regards.
DocVikingo
