MEDICATIONS - Medicine for Mountaineering and Other Wilderness Activities - page 528

After the effects of the nasal spray have worn off, swelling of the nasal mucosa and air-
way obstruction recur. Such rebound symptoms are often worse than the initial symptoms.
Witheachsubsequentapplication,thedurationofthespray'seffectstendstobecomeshort-
er.Forthisreason,useofthesprayshouldbelimitedtothehourswhendecongestantaction
is needed to promote restful sleep. When used in this manner rebound is much less severe
or absent.
Pseudoephedrine
Pseudoephedrine (Sudafed® and others) is a systemic decongestant. The drug acts
throughthenervessupplyingthebloodvesselsinthemucosaoftheupperrespiratorytract,
causing those vessels to contract. Excess fluid in the mucosa (edema) is reduced, the mu-
cosashrinkstonormalthickness,andobstructiontothepassageofairisrelieved.Thisdrug
also shrinks the mucosa lining the small canals that drain the sinuses and the eustachian
tubes that drain the middle ears, allowing air or fluid to move through these structures and
helping to avoid aerotitis media, aerosinusitis, or infectious sinusitis.
Precautions: Only a physician should give pseudoephedrine to individuals with high
blood pressure, heart disease, thyroid disease, or diabetes.
Pseudoephedrineactsasamildstimulantandmakessomeindividualsrestlessorjumpy,
whichcaninhibitrestfulsleep.Reducingthedoseofthedrugbyonlytakingpartofatablet
usually prevents these side effects.
ANTIHISTAMINES
Antihistaminesareagroupofdrugsthatblocktheeffectsofhistamine,asubstancereleased
duringallergicandinflammatoryreactionsandconsideredresponsibleformanysymptoms
of allergy. In addition, some of these agents can prevent or reduce symptoms of motion
sickness.
Precautions: All antihistamines have a tendency to cause drowsiness, although in-
dividual susceptibility varies. Some more recently developed agents produce much less
drowsiness,buteventhosedrugsarenotcompletelyfreeofthissideeffect.Someareavail-
able over the counter. Anyone who has taken an antihistamine must be very careful about
engaging in activities for which drowsiness could be a hazard, particularly driving a car.
Dimenhydrinate, Meclizine, and Cyclizine
Dimenhydrinate (Dramamine®, Benadryl®, and others), meclizine (Bonine® and Ant-
ivert®), and cyclizine (Marezine®) are antihistamines used primarily to control motion
sickness. All should be taken about one hour before embarking on a trip. All are fairly ef-
fective against allergies.
Precautions: All antihistamines have a tendency to cause drowsiness, although indi-
vidual susceptibility varies. Anyone who has taken an antihistamine must be very careful