Taking That Little Blue Pill? Keep Your Feet On The Ground
By Dr. Erwin Samuelson, AME and Jon Thornburgh, CFI
(This is the first of a
series of articles about aviation medicine. Many would-be pilots
forgo flight instruction because they erroneously believe that they
could not pass an FAA flight physical. For example, some people
still believe that one needs 20/20 vision to become a pilot, which
is not true. Other pilots are unable to pass the physical when they
first see an Aviation Medical Examiner (AME), but they eventually
obtain their medical certificates after additional paperwork is
submitted to the FAA. Unfortunately, some pilots are precluded from
ever being able to obtain a medical certificate.
These series of articles will discuss why some pilots can
pass a flight physical while others cannot. It will also discuss
the options available if someone has a problem on the initial
medical examination. Finally, these articles will discuss general
health issues, and answer questions about medication, fatigue, deep
vein thrombosis, stress, high blood pressure, and other
concerns.)
Some types of flying do not require a medical examination. A
pilot does not need to have a medical certificate to fly an
ultralight, a glider (including a motorglider) or a balloon.
However, the FAA expects pilots to use good judgment and stay out
of the air if he knows that he has a medical problem that would
make flying dangerous. This rule also goes for pilots who have
passed a flight physical. Just because one has a current medical
certificate in his wallet does not mean that he should fly if he is
fatigued or has the flu.
In some cases a person should ground himself for reasons that he
may not suspect. Obviously, he should not fly if he is temporarily
taking medicine that has instructions which say that one should
"not drive an automobile or operate heavy machinery." But what
about less obvious medication, such as nose drops (antihistamine)
or allergy pills such as Zyrtec or Claritin? What about Nexium, the
highly advertised "purple pill" taken to combat heartburn?
To get things started, we'll address a sexy topic, which is
guaranteed to arouse attention--Viagra.
Although Viagra is a
prescription medicine, most physicians who are general
practitioners have little idea if the drugs they prescribe will
have any effect on the operation of aircraft. In fact, the only
person who has such specialized knowledge is an Aviation Medical
Examiner. Theoretically, a pilot should consult his AME before
taking any medicine at all, including Viagra.
Viagra is the patented name for sildenafil citrate. Here's a
brief description of how sildenafil works, which will make you an
expert on the subject.
When sexually stimulated, the body releases nitric oxide. This
in turn activates the enzyme guanylate cyclase, which increases the
level of cyclic guanosine monophosphate, which in turn increases
blood flow to the penis. Unfortunately, phosphodiesterase Type 5,
if present in the body, can counter the effectiveness of cyclic
guanosine monophosphate.
What does sildenafil (Viagra) do? It suppresses
phosphodiesterase Type 5. Viagra, in short, allows cyclic guanosine
monophosphate to do its job. However, in addition to affecting
phosphodiesterase Type 5, sildenafil also affects phosphodiesterase
Type 6.
Unfortunately, phosphodiesterase Type 6 is a retinal enzyme
involved in phototransduction, which means that Viagra can cause
the impairment of blue-green color discrimination. About three
percent of Viagra users are affected, and report a "bluish tint" in
their vision for up to six hours. As luck would have it, blue and
green lights are used on airport taxiways.
In addition, the hypotensive effect of nitrate is aggravated by
sildenafil. This can (and has) caused cardiac arrest by Viagra
users, although it appears that the victims may have had a
pre-existing cardiac condition. Viagra has also been reported to
cause headaches.
Aviation physicians recommend that a pilot refrain from
operating an aircraft for six hours after taking Viagra. This is
especially true if he intends to fly at night. Of course, this also
means that a pilot should definitely not use Viagra to enhance his
performance while joining the "mile high club," in which membership
is achieved by sexual activity a mile above the earth. The
combination of a sexual exertion at a 5,000 foot altitude at night
could prove a deadly combination for a pilot and his loved one.
Since Viagra is often taken by "senior" pilots, it should be
noted that the body takes 40% longer to metabolize sildenafil after
the age of 65.
Every time a pilot takes
his aviation physical he completes FAA Form 8500-8, which contains
19 medical questions (with additional alphabetical subsections.)
Question number 17 asks "Do you currently use any medication --
prescription or nonprescription?" Many pilots fail to mention
Viagra, either because they're embarrassed to say "yes," or because
they don't even think of Viagra as "medicine." Before getting a
prescription for Viagra, a pilot should at least call his AME and
ask if the doctor thinks there might be any problems, and if it
will be necessary to report the use of Viagra when he takes his
next physical.
In any case, remember to wait six hours before flying after
using Viagra. (Six hours from Viagra bottle to throttle.)
About the authors:
Dr. Erwin Samuelson has been a Senior Aviation Medical Examiner
for 25 years, and is a Diplomat American Board of Family Practice.
He is the author of a pamphlet entitled "Aviation Medicine -- A
Survival Guide" which can be seen at his website. Dr. Samuelson is
also a contributor to Pilot Medical Solutions, which specializes in
assisting pilots in regaining their medical certificates after
refusal by the FAA. His e-mail address is DrErwin@aol.com.
Jon Thornburgh is an ultralight and FAA flight instructor and
the author of numerous aviation articles. Some of his articles are
archived at www.ultraflight.com/JonThornburghFrame.htm.
Jon's e-mail address is JonThornburgh@pocketmail.com
.