'Acetazolamide', sold under the trade name 'Diamox', is a
carbonic anhydrase inhibitor that is used to treat
glaucoma,
epileptic seizures,
benign intracranial hypertension,
altitude sickness,
cystinuria, and dural ectasia. Acetazolamide is available as a
generic drug and is also used as a
diuretic.
Uses
General
Acetazolamide is often used in the treatment of various diseases. For glaucoma sufferers, the drug decreases fluid formation in the
eye resulting in lower intraocular pressure. In epilepsy, its main use is in
absence seizures, with some benefit in other seizure syndromes. It is also used to decrease generation of
cerebrospinal fluid in
benign intracranial hypertension and has also shown efficacy in autosomal dominant hyperkalemic periodic paralysis. It has also been demonstrated in drug trials to relieve symptoms associated with dural ectasia in indivduals with
Marfan Syndrome.
Acute mountain sickness
Acetazolamide is best taken
prophylactically, anywhere between 125 milligrams (mg) to 500 mg per day, starting a few days before going to the higher altitude. The drug forces the
kidneys to excrete
bicarbonate, the
conjugate base of
carbon dioxide. By increasing the amount of bicarbonate excreted in the urine, the blood becomes more acidic. Acidifying the blood stimulates ventilation, which is beneficial during acclimatization. Others only take it when
symptoms begin to appear so they can tell whether the drug really has any benefits for them, while some people have reported that it relieves mild cases of acute mountain sickness, it is best taken prophylactically.
Note that acetazolamide is not an immediate fix for acute mountain sickness; it speeds up
acclimatization which in turn helps to relieve symptoms. This may take up to a day or two, and requires waiting without any further rapid ascent. It is often advisable to descend if even mild acute mountain sickness is experienced. If serious sickness is encountered, descent is considered mandatory unless other circumstances present greater danger.
Side-effects
Common
side effects of using this drug include
numbness and tingling in the fingers and toes, and
taste alterations (
parageusia), especially for carbonated drinks; both are usually due to mild
hypokalemia (low
potassium levels). Some may also experience blurred
vision but this usually disappears shortly after stopping the medication. Acetazolamide also increases the risk of developing calcium oxalate and calcium phosphate kidney stones. Everyone will experience more frequent
urination as a result of using acetazolamide. One should drink more fluids than usual to prevent
dehydration and
headaches. Acetazolamide prolongs the effects of amphetamines and related drugs.
Contraindications
Acetazolamide should not be taken by individuals if:
★ They have
sickle cell anemia
★ They are
allergic to
sulfa medications
★ They are allergic to any carbonic anhydrase inhibitor
★ They have
liver or
kidney disease
★ They have
adrenal gland failure (i.e.
Addison's disease)
★ They have
diabetes
★ They are pregnant or nursing mothers
Myths
★ 'Acetazolamide covers up symptoms.' Not so: Acetazolamide speeds up acclimatization which in turn helps to alleviate symptoms. However, if you still feel sick, you need to stop ascending immediately.
★ 'Acetazolamide prevents acute mountain sickness from getting worse.' Not so: If your symptoms are not improving, continued ascent can lead to
HAPE or
HACE.
★ 'Stopping the drug causes symptoms to worsen.' Not so: Your body will just return to its own acclimatization rate. If you are already acclimatized, the drug will not change that fact.
References
★ ''Going Higher: Oxygen Man and Mountains'' by Charles Houston, M.D., Fifth Edition, 2005. ISBN 0-89886-631-6.
★ ''Complete Guide to Prescription & Non-Prescription Drugs'' by H. Winter Griffen, M.D., Sixth edition, 1989. ISBN 0-89586-754-0.
★ http://www.ismmed.org/np_altitude_tutorial.htm
★ ''Dural Ectasia in the Marfan Spine: Symptoms and Treatment.'' November 27, 2006. http://www.spineuniverse.com/displayarticle.php/article922.html
★ ''Diamox - Quoted from the Physician's Desk Reference 1993'' http://www.climber.org/gear/diamox.html