A recurring topic of discussion is altitude sickness and treatment.AMS (acute mountain sickness)Time and a distinct lack of resources can quickly elevate thedangers of a medical emergency. High Altitude Pulmonary Edema (HAPE),High Altitude Cerebral Edema (HACE), and retinal hemorrhagingare all problems which can take place in some individuals as lowas 5-8,000 feet. You can read references, but you have a responsibilityto be in reasonable physical shape, drinking plenty of fluids.But the important thing to realize is that you have a MARGIN of safetythat you are cutting.

You should consult your physician about your special needs.Diamox or Previtin should not be taken lightly. [Do you understand the concept of body/drug interactions?]Reactions to other drugs (even aspirin), allergries can differ athigher elevations. See a physician.

Another topic where urban thinking can harm you.Drug treatment is not a substitute for descending. [Do you understand the concept of body/drug interactions?]

Gamow bags have been discussed as an expensive measure (perhaps mostuseful for high altitude expeditions). Bottled LO2 is also a possibility.

The medical definition of what constitutes a high altitude starts at 8,000 ft.This is the elevation where the PO2 is .75 that of a standard atmopshere.14,000 ft. is .666 (2/3) a ATM, and 18,000 ft. is 1/2 an ATM. This is clearlynon-linear [check your linear thinking at the door]. So the problem rangesare: 8,000-14,000 ft. 14,000-18,000 ft. Above 18,000 ft.

Diamox is a potent carbonic anhydrase inhibitor, effectivein the control of fluid secretion (e.g. some types of glaucoma),in the treatment of certain convulsive disorders (e.g. epilepsy),and in the promotion of diuresis in instances of abnormalfluid retention (e.g. cardiac edema). Diamox is an enzyme inhibitor that acts specifically onthe hydration of carbon dioxide and the dehydration ofcarbonic acid. In the eye, this inhibitory action decreasesthe secretion of aqueous humor and results in a drop inintraocular pressure, a reaction considered desirable incases of claucoma.

The diuretic effect of Diamox is dueto its action in the kidney on the reversible reactioninvolving hydration of carbon dioxide and dehydration ofcarbonic acid. The result is renal loss of HCO3 ion, whichcarries out sodium, water, and potassium. Diamox Sequels sustained-release capsules provide prolongedaction to inhibit aqueous humor secretion for 18 to 24hours after each dose, whereas tablets act for only 8 to 12hours.

Blood concentrations of Diamox peak between 3 to 6hours after administration of Sequels, compared to 1 to 4hours with tablets. Placebo-controlled clinical trials have shown that prophylacticadministration of Diamox at a dose of 250mg every 8 to 12 hours(or 500mg Sequels once daily) before and during rapid ascentto altitude results in fewer and/or less severe symptoms (suchas headache, nausea, shortness of breath, dizziness, drowsiness,and fatigue) of acute mountain sickness (AMS). Pulmonaryfunction is greater in the Diamox treated group, both insubjects with AMS and asymptomatic subjects. The Diamoxtreated climbers also had less difficulty in sleeping.

Diamox therapy is contraindicated in situations in which sodiumand/or potassium blod serum levels are depressed, in cases ofmarked kidney and liver disease, in suprarenal gland failure,and in hyperchloremic acidosis. It is contraindicated inpatients with cirrhosis because of the risk of developmentof hepatic encephalopathy.

Fatalities have occurred, although rarely, due to severereactions to sulfonamides including Stevens-Johnson syndrome,toxic epidermal necrolysis, fulminant hepatic necrosis,agranulocytosis, aplastic anemia, and other blood dyscrasias.

Caution is advised for patients receiving concomitanthigh-dose aspirin and Diamox, as anorexia, tachypnea,lethargy, coma, and death have been reported.

Increasing the dose does not increase the diuresis, and mayincrease the incidence of drowsiness and/or paresthesia.Increasing the dose often results in a decrease in diuresis.

Gradual ascent is desirable to try to avoid acute mountainsickness. If rapid ascent is undertaken and Diamox is used,it should be noted that such use does not obviate the needfor prompt descent if severe forms of high altitude sicknessoccur, i.e. pulmonary edema or cerebral edema.

Long term studies in animals to evaluate the carcinogenicpotential of Diamox have not been conducted. In a bacterialmutagenicity assay, EE was not mutagenic when evaluatedwith and without metabolic activation.

The drug had no effect on fertility when administered in thediet to male and female rats at a daily intake of up to fourtimes the maximum recommended human dose. Diamox has been shownto produce birth defects of the limbs in mice, rats, hamsters,and rabbits. There are no adequate and well-controlled studiesin pregnant women. EE should be used in pregnancy only if thepotential benefit justifies the potential risk to the fetus.Because of the potential for serious adverse reactions in nursinginfants from EE, a decision should be made whether to discontinuenursing or to discontinue the drug, taking into account theimportance of the drug to the mother.

The safety and effectiveness of Diamox in children havenot been established.

Adverse reactions, occurring most often early in therapy,include a "tingling" feeling in the extremities, hearingdysfunction or tinnitus, loss of appetite, taste alterationand gastrointestinal disturbances such as nausea, vomiting,diarrhea, and occasional instances of drowsiness and confusion.

No data are available regarding Diamox overdosage in humans asno cases of acute poisoning with this drug have been reported.Animal data suggest that Diamox is remarkably non-toxic. Nospecific antidote is known. Treatment should be symptomaticand supportive. Electrolyte imbalance, development of anacidotic state, and central nervous system effects might beexpected to occur.

Dosage is 500mg to 1000mg daily, in divided doses using tabletsor Sequels as appropriate. In circumstances of rapid ascent,such as in rescue or military operations, the higher dose levelof 1000mg is recommended. It is preferable to initiate dosing24 to 48 hours before ascent and to continue for 48 hours whileat high altitude, or longer as necessary to control symptoms. Store at controlled room temperature (59 to 86 deg F).

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