DefinePK

Abstract

Acute mountain sickness (AMS) syndrome is a life threatening condition, which can best be managed by the descent. However, occasionally descent is impossible because of extreme weather, storms, avalanche conditions, enemy’s encounter, or because the patient is too ill to move and beyond the reach of rescue services. The climber puts himself at extreme risk by choosing to ascent with symptoms clearly recognisable as those of AMS. His remarkable recovei should not seduce other high altitude sejourners into ignoring their symptoms and continuing to ascend while hoping for pharmacologic ‘cure’. The pathophysiologic nature and effec­tive pharmacologic treatment of AMS syndrome remain to be defined. Most people tend to underestimate the potential seriousness until it is too late for the person to make an easy descent. Various pharmacologic agents have been used for the treatment and prevention of AMS.
Acetazolarnide (Az) has been used for nearly 20 years to prevent or attenuate AMS. The reaction CO2 +H2OAH2CO3 is catalysed by carbonic anhydrase (CA) in red blood cells, lungs, brain and other organs. Az is a reversible and specific inhibitor of CA. There have been many studies demonstrating that Azaffects PCO2 values inblood, alveolar and brain tissue. The respiratory events include hyperventilation and a pro­found fall in alveolar PCO2 (PACO2), and arterial PCO2 (PaCO22) increases slightly inin-vivo studies1. In a study2. Az not only reduced the features of AMS but also reduced the muscle and fat loss and increased exercise performance in acclimatised subjects. One clinical trial3 on 20 subjects at 5000 m showed reduced symptoms of AMS (P