Table 2.

Medical therapy for high-altitude illness

Agent	Indication	Dose	Comments
Oxygen	All high-altitude illnesses	2-4 lts by cannula or mask initially, then 1-2 lts/min or titrate dose until SaO2 > 90%	Life saving for HAPO; improves headache within minutes in AMS
Portable hyperbaric chamber	All high-altitude illnesses	Depends on model; 2-4 psi for a minimum of 2 hrs; continued as long as necessary	Effects quivalent to administration of lowflow oxygen; can be lifesaving; does not require oxygen; can add supplemental oxygen by cannula or mask if necessary.
Acetazolamide	Prevention of AMS	Acetazolamide (125-250 mg BD) beginning one day before ascent and continuing for 2 days at high-altitude.	Sulfonamide reactions possible; should be avoided by breast-feeding women; can be taken episodically for symptoms; no rebound effect.
	Treatment of AMS	250 mg PO BD until symptoms resolve.
Dexamethasone	Prevention of AMS	2 mg q 6 hourly or 4 mg q 12 hourly PO	can be lifesaving for AMS or HAcO; effects evident in 2-8 hrs;
	Treatment of AMS	4 mg q 6 hourly	no effect on acclimatization;
	HAcO	PO/IM/IV	no value in HAPO.
Nifedipine	Prevention of HAPO	20-30 mg of extended release formulation PO q 12 hourly	No value in AMS or HAcO; not necessary if supplemental oxygen available.
	Treatment of HAPO	10 mg PO initially, and then 20-30 mg of extended release formulations PO q 12 hourly
Aspirin	Prevention of headache	325 mg PO q 4 hourly for a total of 3 doses	Not proven for treatment.
Ibuprofen	Treatment of headache	400-600 mg once PO, may be repeated.	Not proven for prophylaxis

HAPO – high altitude pulmonary oedema, AMS – acute mountain sickness, psi – pounds per square inch HACO – high altitude cerebral oedema, PO – per orally, q – each quantity, hrs – hours, SaO2 – saturation of oxygen in blood, BD – twice daily, mg – milligrams, lts – liters