In September 2017, two of my best friends and I toured Peru.
At the time, we all lived in Johannesburg, considered high in altitude at 1,600 meters.
High altitude = 1,500 to 3,500 meters (4,900 to 11,500 feet).
On our Peru trip, we visited a few high-altitude destinations.
- Arequipa at 2,335 meters
- Machu Picchu at 2,430 meters
- Cusco 3,399 at meters
We reached a 4,910-meter altitude viewing point en route into the Colca Canyon. This is classified as a very high altitude.
Before we left South Africa, we researched altitude sickness medication and other treatments. Joss, Judy, and I decided not to take anything prescribed with us.
How did we do on our trip?
At the end of this article, I will tell you about our experience and give you 5 tips to survive high altitudes.
But first, let’s recap the basics.
What is altitude sickness?
As you travel higher from sea level, the air gets ‘thinner,’ meaning the oxygen content decreases. Every lung full of air you breathe in contains less oxygen, affecting your blood’s oxygen content. Your body is clever and will adjust to this, but slowly. If you go up to high altitude too quickly, your body doesn’t have the chance to adapt, and you get ill.
The process of adjustment to high altitude is called acclimatization.
@ researchgate.net
Are there different severities of altitude sickness?
Yes, there are.
Acute mountain sickness (AMS)
This is the most common form of altitude sickness. If you are ever unlucky enough to experience altitude sickness, this is the type you hope for.
High altitude cerebral edema (HACE)
A severe form of altitude sickness. Brain swelling starts after 2 to 5 days. This is rare, occurring in 0.5 to 1% of people. It usually occurs at over 4,000 meters (13,100 feet), although it has been reported over 2,500 meters (8,200 feet). 8
High altitude pulmonary edema (HAPE)
As with HACE, this is rare and starts after 2 to 5 days. The lungs fill with fluid.
How do you know if you have AMS?
“If you’re at a high altitude and develop a headache, you most likely have AMS.”
A headache is the most common, and usually the first symptom to develop.
Nausea, vomiting, loss of appetite, exhaustion, insomnia, dizziness, and feeling faint can also occur.
Altitude Sickness Medication And Other Treatments
How can you prevent AMS?
Go higher, slower
How high is too high?
- AMS is rare below 2,440 meters (8,000 feet).
- You will likely get sick above 3,350 meters (11,000 feet) if you haven’t acclimatized. 2
How fast is too fast?
Recommendations for acclimatization are as follows: 2
- Above 2,440 meters (8,000 feet), you should have a rest day to get used to the new altitude and only ascend 500 meters (1,600 feet) daily.
- Above 4,500 meters (14,800 feet), rest for two days every 300 meters (1,000 feet).
Prescribed medication
Acetazolamide
I have often prescribed acetazolamide to patients. Some traveled for business to mines at high altitudes in South America. Others trekked up Mount Kilimanjaro, Aconcagua, or Everest Base Camp.
According to C. Davis et al., this is the prevention option of choice. 1 It is tried and trusted.
You must start the acetazolamide 48 hours before your trip to high altitude and continue it for 48 hours at high altitude or as needed.
Nifedipine
Nifedipine is a blood pressure medication. Over the years, a few patients traveling to high-altitude destinations enquired about it.
The fact is that it will not prevent AMS, only HAPE. 3 So, nifedipine will usually only be useful for thrill seekers.
Because of side effects and the risk of low blood pressure, this should be supervised by a doctor with experience in high-altitude medicine.
Erectile dysfunction medication
You heard correctly, although it is not registered for altitude sickness prevention.
It seems that sildenafil (Viagra) is used ‘off-label’ for the treatment of HAPE but does not prevent AMS.
Tadalafil (Cialis) might be an unusual prevention option for AMS in the future, according to a study. 7
Read about the South Korean government Viagra scandal reported by CNN in 2016.
Coca leaves
South American locals use coca to prevent altitude sickness.
Science doesn’t believe it works.
“Even though there are no definitive data supporting coca use for the alleviation of symptoms incurred at high altitude, travelers continue to use this product, rather than pharmaceuticals with proven benefits.” 4
Other basic steps
While at altitude,
- don’t smoke,
- avoid alcohol, and
- keep hydrated.
Although this won’t prevent AMS, smoking, drinking alcohol, and being dehydrated will worsen symptoms.
How can you treat AMS?
Get to a lower altitude.
This is the most important treatment. It could be anywhere from 300 to 1,000 meters (1,000 to 3,300 feet) until the symptoms ease.
A doctor should supervise taking medication like nifedipine and dexamethasone (a cortisone). Organize very high-altitude adventures using an experienced company with access to medical help. HAPE and HACE can be life-threatening.
How did our 2017 Peru trip go?
We left Arequipa (2,335 meters), traveled to a viewpoint (4,910 meters), and then continued down to the canyon village of Cabanaconde (3,303 meters) overnight.
We had decided not to take acetazolamide for the following reasons.
- We believed we had a head start living at an altitude of 1,600 meters.
- We didn’t want to take a new medication while on holiday in the middle of nowhere.
- The side effects of acetazolamide are similar to the symptoms of AMS.
- We were only at 4,910 meters above sea level for 30 minutes before descending to 3,600 meters again.
- We stayed in Arequipa overnight before the ascent.
We had heard about coca before leaving South Africa.
When our driver and guide picked us up in Arequipa, the first thing they brought out for us was a bag of coca leaves. Within a few hours, we would travel to very high altitude, almost 5,000 meters above sea level, on our way to Colca Canyon. They encouraged us to try coca and reassured us it would not make us high. We decided to give it a go; there was nothing to lose.
We drank sugary coca tea at stops en route, which wasn’t as bad.
Photo credit – Jocelyn Broderick
We chewed the leaves at intervals, but I cannot remember how much or how often. This was not very pleasant; coca leaves are an acquired taste.
Photo credit – Judy Ditchfield
Poor Joss got AMS.
She was incredibly nauseous and had a headache, dizziness, and severe fatigue when we reached Cabanaconde. She was out for the count that night but improved the next morning.
Judy felt hazy.
I had a headache, was very tired but still functional. I have to admit that I had a G&T with supper. I also did not sleep well.
“Sleep disturbances are a symptom of AMS. I could not fall asleep, but think it was because of the volcano erupting intermittently.”
What could we have done differently?
It is impossible to predict who will get AMS.
Flying from sea-level Lima to Arequipa, at over 3,000 meters, shocks the system, even with a Johannesburg altitude headstart. If I were planning the same trip to the Colca Canyon, I would spend two nights in Arequipa. There was enough for us to do.
I would consider taking acetazolamide if you don’t have contraindications. It might prevent you from losing precious holiday time. I am not sure if Joss would agree.
The 5 top tips after our experience
- Take acetazolamide for prevention. Discuss with your doctor if it is an appropriate option for you. It is well-tolerated, and most people don’t have side effects.
- Do a one-day home trial of acetazolamide to see if you develop side effects.
- Stay two nights at a location between sea level and your destination. Make sure you acclimatize.
- Drink lots of water. Make sure you are hydrated.
- Avoid alcohol and smoking at high altitudes.
If you love to travel, read my posts on 15 essential medications to pack and how to boost your travel medicine kit.
References
- Davis, C., & Hackett, P. (2017). Advances in the Prevention and Treatment of High Altitude Illness. Emergency medicine clinics of North America, 35(2), 241–260. https://doi.org/10.1016/j.emc.2017.01.002
- Cleveland Clinic medical. (2023, August 21). Altitude sickness: Not always an uphill battle. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/15111-altitude-sickness
- Hohenhaus, E., Niroomand, F., Goerre, S., Vock, P., Oelz, O., & Bärtsch, P. (1994). Nifedipine does not prevent acute mountain sickness. American journal of respiratory and critical care medicine, 150(3), 857–860. https://doi.org/10.1164/ajrccm.150.3.8087361
- Prince TS, Thurman J, Huebner K. Acute Mountain Sickness. (Updated 2023 Jul 10). In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430716/
- Biondich, A. S., & Joslin, J. D. (2015). Coca: High Altitude Remedy of the Ancient Incas. Wilderness & Environmental Medicine. https://doi.org/10.1016/j.wem.2015.07.006
- Carlsten, C., Swenson, E. R., & Ruoss, S. (2004). A dose-response study of acetazolamide for acute mountain sickness prophylaxis in vacationing tourists at 12,000 feet (3630 m). High altitude medicine & biology, 5(1), 33–39. https://doi.org/10.1089/152702904322963672
- Leshem, E., Caine, Y., Rosenberg, E., Maaravi, Y., Hermesh, H., & Schwartz, E. (2012). Tadalafil and acetazolamide versus acetazolamide for the prevention of severe high-altitude illness. Journal of travel medicine, 19(5), 308–310. https://doi.org/10.1111/j.1708-8305.2012.00636.x
- Jensen JD, Vincent AL. High Altitude Cerebral Edema. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430916/
