|
|
Fishermen's Journal |
MOTION SICKNESS
by Paul Carnes, M.D.
MOTION SICKNESS
What causes
motion sickness? Well it involves the inner ear and three canals called the semicircular
canals. These canals exist in the three different planes of space, i.e. up-down,
left-right and front-back. These canals exist so that we can live in a three dimensional
world and stay balanced as we move around (some better than others). Within each of these
canals are small calcium deposits that are called otoliths (ear stones). Anytime we move
out of a particular plane of space these little stones move and let our brain know via
nerve transmissions. Now in most situations of movement this is not a problem for the
brain to handle. However in some situations in which the movement in and out of these
planes of space are chaotic (like in a boat, car or airplane) the brain may misinterpret
the nerve transmissions. For some this may eventually cause N/V.
Nausea and subsequent vomiting can be exacerbated by many different reasons. Input
from many of the peripheral senses can contribute to nausea. For example visual and
olfactory (smell) input can in many people initiate nausea and vomiting (N/V). And
of course taste and consumption of some foods/liquids can initiate N/V. Although I do not
know of any cases of
auditory (hearing) induced N/V, I speculate it may be possible (besides the times when
people say, "hearing that just makes me sick" :)). Many medical conditions may
also cause N/V. Some of these include inner ear infections, diabetes, gall bladder disease
and dehydration to name a few conditions. Many medications are also suspect, including
some chemotherapy agents and antibiotics (there are too many to list here). My reason for
explaining all of these causes are because all may worsen N/V initially caused by motion
sickness.
How do we treat motion sickness? Well for some, like me, I don't take anything because
I've never gotten sea sick to the point of vomiting. For others medications are a must.
Most of these medications are taken orally; however some can be taken via a rectal
suppository (e.g. Compazine) or some even in a gel that is applied to the skin (e.g.
Trans-derm Scopolamine and
Compazine). There are a number of different medications that are effective. Below I will
describe some of these classes of medications. How do they work? Well pretty good for most
people :) Actually most of these drugs either work in the area of the brain that
receives the nerve impulses from the semicircular canals or affecting the nerve impulses
directly. There are
basically five or six classes of drugs that work effectively for N/V. Not all of
them however are effective in preventing motion sickness. Some though are effective once
N/V has been initiated secondary to motion sickness. The three classes of drugs that are
effective for motion sickness include:
Antidopaminergics: for example Compazine
Antihistamines: for example Meclizine (Bonine, Dramamine II), Cyclizine (Marezine) and
Diphenhydramine (Benadryl), and Dimenhydrinate (Dramamine)
Anticholinergics: Scopolamine (Trans-derm Scop)
Many of these drugs have side effects, most prominently sedation, dry mouth, and blurred
vision. For the specific side effects and the contraindications for taking these drugs see
or talk to your doctor and/or pharmacist first.
Another class of drugs worth mentioning is Serotonin receptor antagonists. These
drugs are used very frequently in patients who have N/V while undergoing chemotherapy. But
there might be some usefulness in combating motion sickness related N/V. The most
prominent oral drug in this class is called Zofran (Ondansetron). The most
prominent side effect is headache, followed by fatigue/malaise. The biggest drawback is
the cost of this drug.
All of the medications above can of course be prescribed by a physician. However
only the antihistamines described above can be purchased over the counter. Because of this
fact, these are the most popular medications obtained by the person who has a problem with
motion sickness.
For many people the biggest problem with taking these medications is sedation. It's been
my experience that Meclizine or Cyclizine are the least sedating. However there may be
some individuals that become very sedated with either of these medications.
What about some of the other "non-medication" methods of combating motion
sickness that have been described? I'll discuss some of those below:
1) Looking at the horizon and staying in fresh air. Well looking at the horizon may work
by actually "tricking" your brain in what seems normal. With viewing in the
distance it only takes a small amount of eye movement to see a larger area, thus only
small eye movements are necessary to view a large arc in the visual field. Near sight
vision takes lots of eye movement.
Remember what I said about input of other senses? Also staying closer to the deck of the
boat, and also near the center of the boat will decrease the amount of roll (side to
side), pitch (up and down) and yaw (left to right) you will experience. The fresh air
eliminates the contribution of smells that might contribute to N/V. Besides the smells
below deck, visual cues causing nausea are also intensified.
2) Cannabis. There is medical evidence that the active component in pot,
tetrahydrocannibinol (THC) is effective in decreasing some types of N/V. Besides being
illegal (except for some medical conditions) it has not been proven to help prevent N/V
from motion sickness. How it works is not known.
3) Ginger. There is medical evidence that
this does indeed help relieve N/V. How it works is also not known. Ginger extract can be
found in most health food stores. Remember Ginger Ale does not contain ginger root extract
4) Wrist bands using the accupressure point called P6. Many people claim it works. It may
in some individuals. How it works is unknown; however the Chinese state it works by
balancing the ying and yang of your body.
5) Beer. Beer may work for two reasons, but
it may also worsen N/V for one big reason. First beer initially may keep you well hydrated
and also has a sedating effect (not many people have N/V while asleep). But the bad effect
is that it may eventually cause dehydration. Remember drinking beer may eventually make
you pee like a racehorse. Dehydration is the enemy and will make N/V worse.
6) Rubbing Alcohol. Believe it or not sniffing rubbing alcohol (isopropyl alcohol) may
eliminate N/V for a short time (up to 30 to 60 minutes). If you do this remember these
facts: only sniff a very small amount (i.e. on a cotton ball) of the alcohol for only a
second to two; do not use near a flame or cigarette/cigar; do not use if you are allergic
to rubbing alcohol; if you sniff the alcohol for too long you may get light headed and
faint; do not use if you are pregnant; do not use if you are a minor...etc. See your
own physician before you do this! (yes this is the disclaimer)..
I know this is a lot of information but here are my basic rules if you want to help
prevent motion sickness.
A) Start your medication well before your trip. This does two things. One it tells you
what kind of side effects you might have and two will give the drug time to get into your
system. It also gives you time to switch drugs in case the side effects are too much of a
problem. I think the best over the counter medications are Cyclizine or Meclizine. You
will need a prescription to obtain Trans-derm Scop patches or anything else. For many the
patch is the way to go, especially if a dry mouth doesn't bother you.
B) Keep well hydrated and not with alcohol. I recommend having a little food on your
stomach before your trip. What this does is gives your body a little bit of last minute
energy, especially if you are not able to eat anything else because of motion sickness.
Also if you do get sick people tell me it's better vomiting up something rather than
having the dry heaves. If you do start vomiting try to keep as well hydrated as possible.
Keep away from foods that are harder to digest, like that greasy hamburger.
C) If you do start to get sick stay on deck in a warm and dry place. Try to stay away from
smells that may make things worse. Watch the horizon if you can. Drive the boat if
possible; this will help you look at the horizon. Remember all that "sealegs"
are is that time it takes your brain to get use to the motion of the boat as being
"normal". That's why many still feel that
boat rocking after you get back on dry land. It's your brain telling you that rocking is
normal.
D) If motion sickness is really problematic (e.g. you get car sick easily or have a family
history) you might try ginger extract and/or the wristbands.
E) Lastly see your family physician or local pharmacist if you have any questions. This is
especially important if you have chronic illnesses such as high blood pressure, a heart
condition or diabetes.
Well I hope this helps some of you. This information is by no means to be considered a
complete explanation of motion sickness and its treatment.
Paul P. Carnes. M.D., AKA Pablo
[I met Paul via the Internet nearly as soon as I opened up the
tackle sales end of things. Paul lives in Oklahoma, and was my first customer from
that State. He surprised me with his knowledge of fishing (purchasing Newell reels
no less), and takes several long range trips annually. He didn't always live out in
Oklahoma, he's another transplanted Californian originating from San Diego. You'll
catch Paul popping up on message boards every now and then. If you see a post from
Pablo, let him know you appreciate his articles - lots of good info! Maybe if we're
nice to him, he'll zap over a picture of someone "barking at seals" for this
article. Okay, now, lets all take a kid fishing..."have a mayo sandwich, some
ice cream and candy while we leave the harbor jr?...]