MEDICATIONS - Medicine for Mountaineering and Other Wilderness Activities - page 526

m) altitudes commonly take dexamethasone instead of acetazolamide because they want to
enjoy carbonated beverages, principally beer.
Precautions: Significant side effects from dexamethasone administered for the short
timeperiodsrequiredtoevacuateindividualswithacutemountainsicknessorhigh-altitude
cerebral edema—evacuation should be the principal therapy—are rare. The primary risk is
relying on dexamethasone alone and not evacuating the affected individual to a lower alti-
tude.
Rarely side effects such as euphoria or cloudy judgment have developed after therapy
with dexamethasone.
Prolonged therapy with dexamethasone is associated with major side effects, but such
prolonged therapy should never be needed for altitude problems. Skiers should not take
dexamethasone for more than five or six days.
Nifedipine
Nifedipine(Procardia®andAdalat®)isamemberofaclassofdrugs,thecalciumchan-
nel blockers, used primarily totreat hypertension andcoronary artery disease. Because this
drug lowers pulmonary artery pressure, it has been given to some individuals with high-
altitude pulmonary edema. In studies of individuals with unusual susceptibility to highalti-
tudepulmonaryedema,nifedipinereducedtheincidenceofthatdisorder.However,itsuse-
fulness in other persons has not been established.
Precautions: Nifedipine administered for the time required to evacuate an individual
with highaltitude pulmonary edema would produce few side effects. However, the therapy
forhigh-altitudepulmonaryedemaisdescenttoloweraltitude.Oxygenmaybehelpfuland
should be administered during descent. Nifedipine alone cannot substitute for those meas-
ures.
Nitroglycerin
Nitroglycerin (the explosive compound) relaxes the walls of small blood vessels, per-
mitting them to dilate and increase the flow of blood. It is most commonly used to treat
angina pectoris (severe chest pain associated with inadequacy of the blood supply to the
heart) but dilates all small arteries and can be used to increase the blood flow to other or-
gans or tissues. As the result of dilatation of cerebral arteries, throbbing headaches fre-
quently follow the use of nitroglycerin.
Precautions: The most serious side effect of nitroglycerin therapy is a drop in blood
pressure due to the dilatation of blood vessels. Fainting or—even worse—aggravation of
the cardiac damage could result. Therefore, a person receiving this drug must be closely
attended. The individual should lie down with head lowered if symptoms of faintness or
dizziness appear.