BY DR. DANIEL L.JOHNSON

Over-the-CounterIncompetence

Fatigue is a complex syndrome with manycauses - Mark R. Rosekind, Ph.D., NTSB

Scott banked into his rising wing, feltthe glider rise and raised the nose

because the thermal gust had kickedup his indicated airspeed 20 knots. Hetightened the turn to stay in the lift, lostit anyway. He felt frustrated and tired. Asmall, turbulent thermal - it would kickhim up for most of a turn, then let himdown. The number on his averager wasnot what he expected today.

Then he looked at the display on XC-Soar. His circles were all over the place- intersecting, overlapping, but not con-centric. The broad green flightpath linesshowing good rates of climb were clus-tered together, making criss-crossingarcs through an area of green - it was hewho'd been wandering, not the thermal.

It had been a stressful week at work; the

pressure of a white paper to finish, a newmanager marking the corners of his terri-tory in tedious committee meetings. Lastnight, the forecast promising a great soar-ing day, he'd taken an over-the-countersleep aid - something mild - to make surehe'd be rested for today's 300k triangle.

But at the rate he was going, he'd belucky to make 150k. Somehow, he hadto figure out why he was having troublecoring this thermal. He'd slept well lastnight; he didn't really feel sleepy - maybehe needed to fly more.

We are unawarePerhaps you've noticed there's an un-

derlying principle that motivates theseessays of mine: it's the things we can'tperceive that cause accidents (the badthings we weren't planning).

Today's points are that over-the-coun-ter (OTC) antihistamines imperceptibly

degrade skill, and that we remain un-aware of this degradation for long afterit's begun. This is shown by the figure,Alertness Reports often Inaccurate, from theNTSB. The top line is how vehicle opera-tors feel; the bottom line is how they aresimultaneously perform ing.

Effects of FatigueThe risks to transportation safety, says

the NTSB, are (in this order!), fatigue,medication, alcohol, and distractions.Clues to fatigue, in order, include per-formance errors (85%), recent work/resthistory (65%), circadian factors/jet lag(61%), time on task/time awake (50%),medical issues; both disease and meds(31%), feeling tired (19%), etc.

I show this list to demonstrate to youthat making a mistake is a much better signof fatigue and impairment than feelingtired. In fact, feeling tired is a danger sig-nal that warrants an immediate response.

Fatigue, no matter what the cause,degrades by 20-50% reaction time, judg-ment, memory, attention, communica-tion, mood, and situational awareness. Itincreases irritability, attentional lapses,apathy, and microsleeps. Fatigue degradesevery aspect of human skill or judgment.And fatigue is caused by many things, notmerely lack of sleep.

In this essay, I want to focus on the effectof OTC medications to produce fatigue.

Pilots do use drugsEach decade, the NTSB publishes a

summary of the pharmacological analy-ses of pilots killed in crashes. Each de-cade there are more drugs found, possiblybecause the instrumentation is so muchbettter. The most frequent are OTCmeds, many of which impair responsetime, perception, reasoning, memory orcoordination.

It's always amazing that a few accidentpilots have been using a combination ofimpairing drugs, usually both prescribedand OTC at the same time, often min-gled with a little alcohol. These combina-tions more than add up.

I mention this partly because someglider pilots are medical escapees fromthe FAA medical certification process,and are sometimes taking impairingdrugs such as seizure meds (typicallyfor pain), antidepressants, tranquiliz-ers, sleeping pills, or allergy meds. These

Soaring • October 2013 • www.ssa.org

pilots typically feel just fine, thank you,and we have no benchmark to measureimpairment in a pre-flight check.

Deadly diphenhydramineAlliteration is fun, eh? The truth is

that during the last decade, medica-tions that impair thinking were presentin 12% of pilots involved in fatal acci-dents. Slightly more than half of thesepilots had taken diphenhydramine,most commonly known as Benadryl,also in Nytol, Sominex, Tylenol PM,and many, many other over-the-coun-ter medications.

Let me say this: there is no reason forany sane person to take diphenhydr-amine. It's an old drug with too manyside effects. It is mostly used for allergyand sleep, as it's an antihistamine that issedating. It causes dry mouth, increasedheart rate, agitation (in some), andslowed urination in old men. Why dothis to yourself?

Sedating antihistamines - diphen-hydramine in particular - are the medi-cation found most frequently in pilotswho have had fatal crashes. After takingsedating antihistamines people don't feelsleepy, yet they have difficulty stayingawake and performance is impaired.

For example, a study compared diphen-hydramine (50 mg), alcohol (enoughto get BAG to 0.10%, the legal limit inmost U.S. states), and the non-sedatingantihistamine fexofenadine (AllegraM)(60 mg) on driver performance. Theseare usual doses of each medication.

There were two important findings:First, diphenhydramine was moreimpairing than alcohol. Drivers hadslowed reaction times, delayed per-ception, imprecise maneuvering, and"steering instability." Fexofenadine andplacebo were equivalent.

Second, drivers' own sense of fa-tigue was not related to their degree ofimpairment.

There are better sleep aids and betterallergy meds.

Better sleep aidsMelatonin

The FAA does not disapprove of mela-tonin, but 3 mg or more has been shownto impair alertness into the next day. Irecommend you not take so much. Thephysiologic dose of melatonin is 0.5 to 1

mg once daily. This is not a sleeping aid:it helps manage your circadian rhythm,to improve sleep quality. See SoaringRx, August, 2012, for more details, orhttp://www.danlj.org/~danlj/Soaring/SoaringRx/2012-08-JetLag-P14-17.pdf

Sleeping pillsThe FAA allows only four sleeping

pills, used a maximum of twice eachweek, with a required "down time" af-ter each dose based on their knownpharmacokinetics:

Sedative-hypnotic MedicationDown time after useApprox cost/doseeszopiclone (Lunesta )30 hours$7.70zolpidem (Ambien™)24 hours$.60 / $7zaleplon (Sonata™)6 hours$5.00ramelteon (Rozerem™)24 hours$5.70Frankly, you should use these guide-

lines for driving (and doing intellectualwork!), not just piloting, for most sleepaids have been shown to decrease perfor-mance for many hours after use. It doesn'ttake much intelligence to live a normaladult life, so most people don't notice.

An uncommon but scary event af-ter taking a sleeping medication is sleepdriving, driving after using one, with nomemory of the trip. It's not so good ifyou have a new dent in your fender thenext evening and don't know how itgot there. We like glider pilots to knowwhere they started the flight.

Better allergy aidsThe FAA approves these allergy meds:

The antihistamines fexofenadine (Al-legra™) and cetirizine (Claritin™) forgeneral allergy, and cromolyn (Nasal-crom™) nasal spray or any nasal steroidspray, for nasal allergy. Cromolyn is verynice because it is effective, it has no sideeffects and is OTC. The nasal steroidsare more effective but require a doctor'sprescription and are much more costly.

Cetirizine (Zyrtec™) is less sedating,but is not so much as to be approved forpilots. It's derived from hydroxyzine, a

very effective antihistamine first used asa mild tranquilizer and sedative.

Over-the-Counter junk medsThere are three reasons for a medica-

tion to be sold without a prescription:1: It was already on the market in the an-

cient days when the FDA had no authorityto regulate it, and it was "grandfathered."Examples: diphenhydramine (AdvilPM™,TylenolPM™, many others).

2: It was a prescription drug untilsomething better was developed, so theold stuff was put on the OTC marketlike tattered used clothes handed downto a poor relative. Examples: chlorpheni-ramine (Coricidin™), brompheniramine(Dimetane™), doxylamine (Nyquil™).

Or its side effects are thought tobe safe enough. Examples: meclizine(Antivert™), a drug that doesn't helpdizziness very much; dimenhydrinate(Dramamine™), even less effective -both are sedating antihistamines. AnInternet site says about dimenhydrinate,"...if you take 10-15 of them you willprobably be really tired and quiet andforget everything you are saying you willsee that everything around you starts tomorph slightly..."

3: An actual, rational decision wasmade that the drug is actually safe enoughto use for nearly everyone. Examples: theulcer drugs cimetidine, famotidine, andranitidine (TagametIM, Zantac™, andPepcid™). All are available in tablet sizes25% of the prescription dose.

Why the FDA requires manufactureof an ineffective dose of a safe medica-tion is related to the belief that peoplewidely double and redouble the doses ofOTC meds - scary when you think ofthe long duration of diphenhydraminein the body or the toxicity of acetamino-phen (Tylenol™) for the liver. And arealistic concern, given the quote twoparagraphs back.

And, of course, some drugs are legaland unrestricted because of political orcultural pressures. Alcohol, for example.

Many people use alcohol as a sleep aid,though unwisely because they don't un-derstand its pharmacology. "Eight hoursfrom bottle to throttle" is a useful rule fora single drink. Alcohol produces sedationand drowsiness for about four hours; af-ter this, the alcohol has been convertedto aldyhydes, which produce stimulation,

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hypertension, and wakefulness that lastabout eight hours more. The actual dura-tion of drowsiness and later stimulationdepend on the amount of alcohol drunk,your body size, and your sex.

The ideal time to take alcohol for thismedicinal effect is when you wake upduring the night and can't sleep. A glassof wine or beer will help you sleep for 4hours or more, then help keep you awakethrough the next morning. But I knowof no one who drinks this way!

My bottom-line thoughtsMy job is prescribing drugs. Let me

say that they are useful, but they arenot magic pixie dust, and they alwayshave adverse effects, which usually aren'tshow-stoppers, but need to be under-stood. Get an explanation of the fineprint, not only the advertising copy!

It's not a good idea to use anythingbefore flight that is disapproved by theAir Force or the FAA. There are alwaysreasons for this disapproval.

Second, if you feel fatigued — wornout, sleepy, demoralized, weak, and soon — please understand that you becameimpaired quite awhile ago and act accord-ingly. There are many causes of fatigue,some of which may be cured by a goodthermal on a brilliant day, so it's alwaysa good idea to examine ourselves aboutthe likely cause. The question is: can Icompetently do what I'm expecting ofmyself? The answer varies.

The Federal Air Surgeon, Dr. FredTilton, says that if for some reason weneed to fly after needing to take a sedat-ing medication, we should wait five half-lives after the dose. As this number maybe hard to find, use 5 times the maxi-mum inter-dose interval on the label.

Read the fine printSedating antihistamines available in

OTC medications include bromphe-niramine, chlorpheniramine, diphen-hydramine, doxylamine, pheniramine,phenyltoloxamine, promethazine, trip-rolidine, meclizine, and dimenhydrinate.There is no reason, ever, to take any of thesedrugs.

ReferencesEditorial. Tilton, F. MD. The Federal

Air Surgeon's Medical Bulletin,Vol. 51,No. 3 August, 2013.

Effects of Fexofenadine, Diphenhydr-amine, and Alcohol on Driving Per-formance. Weiler JM, et al. Ann InternMed. 2000; 132:354-363.

http://www.fda.gov/Drugs/Drug-Safety/InformationbyDrugClass/

Managing Fatigue in Aviation: En-hancing Flight Safety. Mark R. Rose-kind, Ph.D. NTSB Board Member.Presentation to Aviation Safety Coordi-

nators, July 24,2013http://www.ntsb.gov/doclib/speeches/

rosekind/rosekind_07242013.pdf

Impact of Sedating Antihistamines onSafety and Productivity. Kay, Gary G.;Quig, Mary Elizabeth

Allergy and Asthma Proceedings, Vol-ume 22, Number 5, September-October2001, pp. 281-283(3)