Buy Altitude Sickness treatment online without having to see your GP face to face. DrFelix prescribes the prescription treatment Diamox used for high altitude sickness. Diamox is the brand name for the medicine acetazolamide.

Diamox stopped being sold in the UK since April 2015. Acetazolamide, the active ingredient in Diamox is available from our NHS community pharmacy. We still call it Diamox sometimes as this is a more recognisable name but both medicines are clinically identical and equally as effective.

Diamox (acetazolamide) increases the amount of urine produced and changes the acidity of the blood to improve breathing and reduce fluid around the brain and in the lungs. Order Diamox / acetazolamide online today and have it delivered for next day.


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Summary of available medications

Medication Quantity Price
Acetazolamide 250mg 28 to 112 tablets From £29.99

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Acetazolamide (Also known as Diamox)

Medication Quantity Price
Acetazolamide 250mg 28 tablets £29.99
Acetazolamide 250mg 56 tablets £54.99
Acetazolamide 250mg 112 tablets £99.99


All prices exclude prescription fee


What is altitude sickness?

Altitude or high altitude sickness occurs when someone climbs a mountain really quick into a different pressure. The drop in atmospheric pressure prevents you from taking in adequate oxygen and leads to difficult and hard breathing. Most instances of high altitude sickness are not serious and just cause a headache, dizziness and some nausea. In some cases there is a possibility of fluid build-up in the brain or the lungs which can be extremely dangerous.

At what height does altitude sickness happen?

Altitude can occur anywhere around 2500 meters above sea level. This is not a very high height especially for skiers, and the sickness is often mild. The symptoms are much worse for heights above 3600 meters which is 12,000 feet.

At what height does oxygen disappear?

Humans struggle to breathe in any oxygen around an altitude of 4572 meters (15k feet), although professional climbers can acclimatise and go higher it is not possible without an oxygen tank and not for long either. If the atmospheric pressure drops lower than 57%, people pass out.

Is there any treatment for altitude sickness?

Acetazolamide, more commonly known by the brand name Diamox, is the medicine in the UK prescribed for altitude sickness. Acetazolamide works by reducing the symptoms which can occur when you climb above 10,000 feet.

How can you acclimatise?

The best way to acclimatise is to climb gradually with regular stops and rest. You should only climb up to 500 meters a day and take rest for a night for any heights above 3000 meters. If you climb more than this, then descend back down to the 500m mark to sleep at night. As a general rule of thumb you should sleep for 2 nights for every 1000 meters you climb before going any further.

Warnings! Seek immediate medical help if you experience any one of these two:

1. Fluid on the lungs is normally indicated by difficulty in breathing, coughing, blue lips and nails, drowsiness, extremely tired and sometimes death. The main symptom to look out for is shortness of breath just in that person but other people recover fine. 2. Fluid on the brain is indicated by loss of coordination, feeling lethargic, cannot walk a straight line. This is known as High Altitude Cerebral Oedema (HACE). The main symptom to look out for is the inability to think properly and do normal tasks. For both of these conditions, you must descent immediately by at least 1500 feet since delay can be fatal. Oxygen and hyperbaric oxygen are the immediate treatment on top of the hasty descent.

Acetazolamide (Diamox) is a prescription only medicine prescribed for altitude sickness. Diamox was the branded version which stopped being sold in the UK from April 2015. DrFelix offers Acetazolamide on prescription for home delivery. Altitude sickness medicine helps increase urination and changes blood acidity levels. The main aim of this is to make breathing easier and prevent fluid on the brain or lungs.

Acetazolamide is not licensed under altitude sickness treatment in UK but it has been used by doctors for high altitude sickness for a long time.

Mild acute treatment

For headache, fatigue and difficulty with sleeping Take ONE Acetazolamide 250mg tablet twice daily until symptoms resolve, can continue ascent thereafter.

Rapid ascent without acclimatisation

Take ONE Acetazolamide 250mg tablet twice daily. Start one day before climbing and continue for a few days once arrived at the final destination altitude.

Disturbed breathing during sleep

Take HALF Acetazolamide 250mg tablet twice daily (125mg). Continue this dosage until descent to an altitude where sleep is no longer a problem.

Acetazolamide used for short courses does not cause any symptoms in most cases. However like all other medicine, some people have reported the following side effects:

  • Loss of appetite
  • Flushing
  • Dizziness
  • Headache
  • Tiredness
  • Depression
  • Irritation
  • Tingly feeling in fingers and toes

See the Diamox / Acetazolamide patient information leaflet for a more detailed list of the symptoms.