High-Altitude Pulmonary Edema (HAPE) Medication

Updated: Apr 07, 2020
  • Author: Rohit Goyal, MD; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
  • Print

Medication Summary

Drugs are not as effective as descent from altitude and oxygen in the treatment of high-altitude pulmonary edema (HAPE). Nifedipine, by reducing pulmonary arterial pressure, may be effective in treating HAPE. [29] However, in two separate studies, nifedipine did not outperform placebo or oxygen alone. [33, 34]


In general, acetazolamide facilitates acclimatization, but this agent should not be relied on as the sole preventive agent in individuals with known HAPE susceptibility. [2, 3]

The Centers for Disease Control and Prevention (CDC) strongly recommends acetazolamide prophylaxis in all individuals with a prior history of HAPE or HACE, as well as with the following [4] :

  • History of acute mountain sickness and ascending more than 2,800 m in 1 day
  • All people ascending to more than 3,500 m in 1 day
  • All people ascending more than 500 m per day (increase in sleeping elevation) above 3,000 m, without extra days for acclimatization
  • Very rapid ascents

The CDC recommends the following pharmacologic agents and regimens for HAPE prophylaxis [4] :

  • Oral nifedipine (generally reserved for HAPE-susceptible individuals) - 30 mg sustained-release formulation every 12 hours (same regimen for HAPE treatment)
  • Oral tadalafil - 10 mg twice daily
  • Oral sildenafil - 50 mg every 8 hours


Further research is needed before tadalafil or dexamethasone can be recommended over nifedipine for prophylaxis. The Wilderness Medical Society (WMS) advises that diuretics or acetazolamide should not be used for treatment of HAPE, and it makes no recommendation regarding beta-agonists or dexamethasone for HAPE treatment due to insufficient/lack of data. [2, 3] Furthermore, WMS indicates there is no established role for acetazolamide, beta-agonists, diuretics, or dexamethasone in the treatment of HAPE, although dexamethasone should be considered where there is concern for concomitant high-altitude cerebral edema (HACE)

In the setting of concomitant HAPE and HACE, WMS recommends adding dexamethasone to the treatment regimen for patients with HAPE and neurologic dysfunction that does not resolve rapidly with administration of supplemental oxygen and improvement in the patient’s oxygen saturation. [2, 3] If supplemental oxygen is not available, initiate dexamethasone in addition to medications for HAPE in those with mental status changes and/or suspected concurrent HACE. Note the following:

  • Dexamethasone should be administered at the doses recommended for the treatment of HACE.
  • Nifedipine or other pulmonary vasodilators may be used to treat concurrent HAPE and HACE, but avoid lowering mean arterial pressure, as this may decrease cerebral perfusion pressure and thereby increase the risk for cerebral ischemia.

Calcium channel blockers

Class Summary

Nifedipine is used for its pulmonary vasodilating effects.

Nifedipine (Procardia, Adalat)

Nifedipine is used in HAPE for pulmonary vasodilation. It often improves SaO2 modestly within a few minutes.


Carbonic anhydrase inhibitors

Class Summary

These agents are helpful in the prevention of HAPE.

Acetazolamide (Diamox)

Acetazolamide is used in the prevention of HAPE. It is not used in the treatment of this condition. Acetazolamide promotes renal excretion of bicarbonate, which stimulates respiration. For the prophylaxis of altitude illness, start 24-48 hours before ascent and continue for 48 hours after arrival at high altitude.



Class Summary

These agents have profound and varied metabolic effects. They suppress inflammation and the immune response.

Dexamethasone (Decadron)

Dexamethasone alleviates vasogenic cerebral edema and improves endothelial integrity.