Treatment of airsickness with drugs

Abstract

IRSICKNESS is a form of. motion sickA ness to which most people probably are susceptible depending on the duration of flight, type of plane, position in plane and the weather as well as other undetermined factors. Certain factors, such as apprehension and fear, are believed by some to be more important in airsickness than in other forms of motion sickness. Air passengers in both military and civilian life may have had but little flying experience or may fly so infrequently that adaptation does not occur. It is in this group that drugs may be of greatest value. Studies in the air forces have shown that the incidence diminishes rapidly with experience in the air. l The movement of aircraft is highly erratic and depends on the type of aircraft and the weather conditions to so large an extent that other devices have been used for producing motion sickness. The most widely employed has been the simple swing.2 Others have included vertical accelerators3 and rotating chairs.4 A drug for the relief of airsickness should prevent airsickness without producing any other pharmacologic effects. It should be active after oral administration and the onset of action should be immediate. It should not be toxic, habit-forming or cause disagreeable symptoms. At present remedies are available which will decrease the incidence of airsickness to about one-third without producing appreciable side effects. In general the drugs used have been those that have been employed in seasickness or drugs related to these. Most of them are either central nervous system depressants such as barbiturates, central nervous system stimulants such as benzedrine or parasympatholytic agents such as drugs of the atropine series. Various criteria have been employed in evaluating the remedies but in general vomiting alone as the chief criterion is usually the most reliable. It is surprising that many studies have been made on motion sickness with mixtures of drugs without first determining the effectiveness of the component drugs. Frequently the central nervous system stimulants have been incorporated to prevent undue depression and in some as many as seven different drugs have been employed simultaneously.4 The most promising group of drugs have been those with parasympatholytic action such as atropine and related drugs. .Of those of demonstrated effectiveness, atropine, hyoscyamine and hyoscine (scopolamine) are the most effective. On the basis of their effect on motion sickness alone there is not much difference between these three drugs. However, it. has been demonstrated that the suppression of salivation is less with hyoscine than with atropine or hyoscyamine when they are all used in effective doses.5 For this reason hyoscine has been employed most frequently although there is little evidence that it is actually superior in its ability to relieve motion sickness. It has been shown to be effective in seasickness,6 swing sickness7 and airsickness.8*g The doses that have been employed most commonly are 1 .O mg. of atropine sulfate or of hyoscyamine hydrobromide or 0.65 to 0.75 mg. of hyoscine hydrobromide. The onset of action after the oral administration of the drug is not very rapid, about one hour being required for an appreciable suppression of salivation. The actual duration of action of these drugs is not known but there