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Medication and Aircrew
INTRODUCTION
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Over the past 30-40 years, introduction of chemotherapeutic agents with ever greater clinical
effectiveness, but substantially more benign side effects profiles.
o ➪major implications for the medical management of aircrew.
Useful guidelines that adopt a "listing" approach have been published, but such a list takes no
account of the details of the patient's underlying condition or comorbidity.
PRINCIPLES
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The management of most acute conditions will require a break from the demands of a profession
characterized by the daily need to maintain vigilance and rapid response times.
o ➪Short courses of medication (NSAID, ATB, analgesics…) should be accompanied by a brief
period of grounding.
o The return to flying will depend on the resolution of the underlying condition, completion
of the drug treatment and resolution of the possible side effects.
The introduction of long-term drug treatment for any condition has a potential for adverse career
implications.
o Due concern should be given to ensure that there is an adequate and legitimate indication,
without ever prejudicing the most effective and evidence-based management of the
patient.
o Long-term therapy introduction must be shown to be effective in achieving the desired
result and also needs to be effectively monitored in the long term.
o Obligation to ensure that there are no class side effects that would be unacceptable in the
flying environment:
 Subtle impairments of psychomotor function
 Vigilance
 Disturbance of special senses.
 The possibility of individual idiosyncratic drug responses must be borne in mind.
 Insist on a period of grounding at the start of the treatment, ≥ 2 weeks.
 Compatibility with other treatments must be assessed.
A once-daily scheme of drug administration should be the aim, as compliance will suffer from
irregular work patterns and the possibility of time zone changes.
Limit the dose of drugs to the lowest compatible with producing the desired response.
Introduction of a multi-drug approach may be appropriate, such as the modern management of
hypertension.
The risks of sudden withdrawal must be considered and avoided in aviators.
Cautious approach with the use of newly released drugs in the treatment of aircrew. Conservative
management strategies should be a motto until sufficient experience is gained in the general
population.
GENERAL PROBLEMS
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Few drugs have been tested thoroughly in the aviation environment.
However the undesirable effects of modern drugs are explored more vigorously in the modern
litigious environment.
Drugs that appear to be entirely satisfactory on the ground may still be associated with
unexpected side effects in aircrew.
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SPECIFIC PROBLEMS OF DRUG THERAPY
Antihypertensive agents
 Potential influences on flying performance. cf. cardiology notes.
Lipid-lowering drugs
 The number of prescriptions for statins (HMG-CoA reductase inhibitors) increases
exponentially.
o Robust evidence for the effectiveness in both primary and secondary prevention of
vascular disease.
o The excess of sudden deaths among those taking active treatments in the earlier
reports represented a statistical blip that was not supported in the many subsequent
studies.
o Their main side effect is muscle toxicity with the (rare) occurrence of rhabdomyolysis.
 Although some studies have reported an influence on sleep patterns and memory, the large
accumulated experience has shown the statins to be a remarkably safe group of agents.
 If no other contraindication, pilots may be allowed to fly unrestricted while taking statins.
Diabetes mellitus and hypoglycaemic agents
 Insulin-treated diabetes mellitus is entirely incompatible with both professional and private
flying, because of the frequent incidence of hypoglycaemia. (Although some national
authorities may allow private flying under strict conditions).
 Diabetes type 2:
o α-glucosidase inhibitor is free from systemic effects, as it acts on the small intestine to
regular glucose absorption. May be used without restriction in the flying environment.
o Metformin (biguanide) is the usual drug of first choice when lifestyle management isn't
sufficient. It is free from significant risk of induced ➘Glc, and is regarded as acceptable
for professional flying OML.
o Sulphonylureas are associated with a significant risk of ➘Glc and, are unacceptable in
aircrew.
o Glitazones, are accepted for unrestricted professional flying duties, but not if associated
with a sulphonylurea.
H1-antihistamines
 Introduction in the late 80' of antihistamines H1 that were free from sedative effects. However,
experience has shown unexpected and undesirable side effects can still become apparent, even
after many years.
o Terfenadine is associated with a risk of precipitating episodes of life-threatening
ventricular arrhythmias (torsades de pointe). The risk is small, but amplified by the
concurrent administration of agents competing for the hepatic cytochrome P450depedent metabolic pathway:
 Macrolide ATB
 Some antifungal agents
 Grapefruit juice…
 ➪ Few of the H1-antihistamines are now considered entirely safe for use in the aviation
environment. Are accepted:
o Loratadine (Clarytin)
o Des-loratadine (Aerius)
o Fexofenadine (Telfast)
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Anticoagulants
 Serious complication rates of less than 2% per annum have been documented in patients
taking oral anticoagulants.
 Furthermore, the risk of the underlying disease must also be considered.
o e.g. warfarin taken by patients with mechanical prosthetic heart valves:
 Risk of thromboembolism (0.7% per annum)
 Risk of valve failure
 Haemorrhage risk (2.7% per annum)
o ➪Definition the optimal level of anticoagulation, expressed as INR, to achieve the ideal
balance between the risks of haemorrhage and thrombosis.
 Oral anticoagulants are currently not accepted in aircrew. But future progress in the area of a
better control may allow re-examination of the regulation.
Antiarrhythmic agents
 cf. cardiology.
 Limited classes of drugs for use in pilots.
 ß-blockers and sotalol may be acceptable for restricted flying for pilots with paroxysmal AF.
 The pro-arrhythmic potential of many drugs, such as the class 1c agents are rarely acceptable.
 The ophthalmic side effects of amiodarone preclude most pilots using it.
 Increasing emphasis is being directed on rapid developments in intracardiac
electrophysiological ablation techniques.
Anticonvulsants
 Epilepsy is disqualifying for flying.
 However some anticonvulsant drugs are also used in the management of other conditions,
such as neuralgic pain syndromes.
o These disorders are unlikely to be compatible with flying duties in most cases.
 The risk of relapse and central effects from these drugs makes a return to flying inappropriate.
Psychotropic drugs
 JAR does not currently accept any drug of this class for professional flying.
 However, under strict circumstances, FAA and CASA allow professional flying duties OML for
pilots with mild recurrent depression treated with SSRIs.
Immunosuppressants
 Many clinical conditions requiring therapy with immunosuppressant drugs will be
incompatible with flying.
 However the use of low doses to control conditions that have little capacity to challenge the
performance of the aviator may be encountered:
o Uncomplicated psoriasis controlled with low doses of methotrexate
o Chronic active hepatitis controlled on low-dose steroids (≤ 10mg/day) in symptom free
patients.
 Freedom from side effects, control of the underlying disease process and close monitoring are
required in all cases.
Antimalarial prophylaxis
 Professional aircrew, both civil and military, are often required to fly in parts of the world
where chemoprophylaxis against malaria is required.
 Not all possible choices are compatible with flying duties.
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Chloroquine-proguanil has proven remarkably safe, although not free from side effects.
However, increased resistance of plasmodium falciparum to chloroquine often requires
the use of other drugs.
Doxicycline is a useful drug and free of side effects for the flying environment.
Atavoquine-proguanil (Malarone™) is free from adverse influences on psychomotor
performance.
Mefloquine has significant neuropsychiatric effects that render the drug incompatible
with flying duties.
Treatment of erectile function
 The professional pilot population contains large numbers of middle-aged men, in whom
concerns over failing erectile function are not uncommon.
 Identification and treatment of any underlying condition, together with the addressing of any
psychological problem is an absolute requirement.
 Since the late 90', the availability of treatment with phosphodiesterase inhibitors (Viagra™ and
others) has provided an effective solution for many of those patients. But these drugs have
reported side effects, usually mild and short-lived, such as:
o Headache
o Rhinitis
o Disturbance of colour vision
o There should be no flying duty within 12-24 hours after the use of the drug.
Prostatism and α-blocking agents
 Benign prostatic hypertrophy is another relatively common affliction of the mature male.
 Most α-blockers are incompatible with professional flying status.
 However, prostate-selective drug tamsulosin appears to be relatively free from orthostatic
hypotension and thus may be accepted for flying OML.
OTHER POTENTIAL PITFALLS
Over-the-counter drugs
 Potential aeromedical risks of taking OTC agents:
o Analgesics with codeine…
 Aircrew need to adopt a (very) cautious approach to self-medication.
 They should be educated to seek appropriate advice before self-treatment.
Complementary medicines
 Many such preparations contain pharmalogically active ingredients with the potential to
produce unwanted effects and may also have the potential for significant interactions with
prescribed medication;
Drug compliance and time zones
 Wherever possible, once-daily medication should be provided.
 Medication should be taken according to base time where possible. Also relevant for
passengers.
CONCLUSION
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The aviator needs to be aware of his/her responsibility to seek advice from authoritative sources
whenever the initiation of drug therapy is contemplated.
He/she also needs to reflect carefully before taking any agent that might have active
pharmalogical properties.
©Jean-Michel Ferrieux-2011
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