Page 94 - Journal of Special Operations Medicine - Summer 2016

patch that steadily releases 20μg/h for 72 hours has been Adjunct Medication
developed. The patch must be put on 8–12 hours before The most frequently cited side effect of medication used
exposure to allow a steady state of drug to be reached. to prevent motion sickness is sedation. A variety of
This may limit its operational effectiveness because the medications have been used to combat these sedating ef-
user or medical provider has to predict the need for pro- fects, including ephedrine, amphetamines, and caffeine.
phylaxis. Alternatively, an oral or intramuscular loading Amphetamines are controlled substances, with addic-
dose can be used in conjunction with the patch to reach tive properties and concerning side effects that may not
a quicker steady state. Significant research has been di- be suitable for operations. It should be noted that they
1
rected toward the intranasal administration of an aque- have been used and studied, and form the basis of many
ous form of scopolamine, referred to as INSCOP. Much Air Force airsickness regimens. Co-administration of
12
of this research has been conducted by NASA and the 5mg of dextroamphetamine does appear to counteract
Naval Medical Research Unit. Although the reports are the side effect of sleepiness and drowsiness associated
very promising, to the author’s knowledge, no publically with scopolamine. Whether this is an option for the Spe-
published trial results are available. 10
cial Operations Soldier is disputed and is probably left
up to individual unit or military regulations.
Side effects of scopolamine include sedation, blurred vi-
sion, and dry mouth. It can also precipitate acute-angle Ephedrine is readily available and commonly used with
closure glaucoma in those susceptible. In higher doses, it decongestants. It is stimulating and can increase heart
may also cause some confusion. From an operational rate and blood pressure, and cause tremors. Ephedrine
1,2
perspective, the sedation and blurred vision may be a has been studied in combination with promethazine at
significant issue. Special care must be made not to touch a dose of 25mg of ephedrine and was found to decrease
the eyes after applying the transdermal patch, because side effects of sleepiness and drowsiness. 1,13
significant blurred vision can occur.
Caffeine may be a useful adjunct in the Special Opera-
Antidopaminergics tions setting. In one study, when 200mg of caffeine was
This class of drugs has been frequently used in the medi- combined with promethazine, it significantly decreased
cal setting for the treatment of nausea. Promethazine symptoms and improved reaction times. The benefit of
14
and metoclopramide have been used and studied for caffeine is that it is readily available and socially accept-
motion sickness. 1,2
able. Most individuals have been exposed to it and, in
pill form at a 200mg dose, it is not a significant diuretic.
Antiemetics such as prochlorperazine and ondansetron
are both very effective antinausea medications and can
help alleviate vomiting in motion sickness. However, in Performance
very small studies, they have not demonstrated a benefit The key issue from an operational perspective is what
in preventing motion sickness. 11
works and what is going to allow the operator to do
their job. There is very little research comparing the
Benzodiazepines have demonstrated some benefit in pre- various medications in an appropriate head-to-head
venting motion sickness but are limited by the sedating fashion. In one small study of 67 patients, meclizine had
effects. One theory is that this type of medication is the least impact on cognitive effects. It was followed in
1,2
most effective for those who suffer anticipatory motion order by scopolamine, promethazine, and lorazepam. 15
sickness.

1
Table 1 Drug Doses and Typical Onset of Action (based on Benson )
Duration of Action,
Drug Route Dose Time of Onset hours
Scopolamine Oral 0.6mg 30 minutes 4
Scopolamine Transdermal 20μg/h 8–12 hours 72
Meclizine Oral 25–50mg 2 hours 8
Dimenhydrinate Oral 50–100mg 2 hours 8
Dimenhydrinate IV/IM 50mg 15 minutes 8
Promethazine Oral 25–50mg 2 hours 15
IM, intramuscular; IV, intravenous.

80 Journal of Special Operations Medicine Volume 16, Edition 2/Summer 2016