High hopes at high altitudes: pharmacotherapy for acute mountain sickness and high-altitude cerebral and pulmonary oedema.

The pharmacotherapy of prevention and treatment of acute altitude- related problems - acute mountain sickness, high-altitude cerebral oedema and high-altitude pulmonary oedema - is reviewed. Drug therapy is only part of the answer to the medical problems of high altitude; prevention should include slow ascent and treatment of the more severe illnesses should include appropriate descent. Carbonic anhydrase inhibitors, in particular acetazolamide, remain the most effective drugs in preventing, to a large extent, the symptoms of acute mountain sickness, and can be used in the immediate management of the more severe forms of altitude-related illnesses. Glucocorticoids in relatively large doses are also effective preventative drugs, but at present are largely reserved for the treatment of the more severe acute mountain sickness and acute cerebral oedema. Calcium channel blockers and PDE-5 inhibitors are effective in the management of acute pulmonary oedema. Further work is required to establish the role of antioxidants and anticytokines in these syndromes.

Effect of time exposure to high altitude on zinc and copper concentrations in human plasma.

BACKGROUND: Research has focused mainly on the relationship of zinc and copper contents and physical stresses like running, cycling, etc. It has also been reported that other forms of stresses change the concentration of these trace elements in humans. However,there are no reports on the effects of high altitude induced hypoxic stress on the plasma levels of these metals. Since hypoxia is one of the important stresses, we considered it appropriate to observe the changes in the levels of zinc and copper concentrations and in certain related zinc and copper enzymes and hormones in the plasma of human volunteers on acute induction to high altitude. From these findings, we intended to ascertain whether supplementation of these trace elements would be required for optimal health under such conditions. HYPOTHESIS: On acute induction to hypoxia, contents of these trace elements may change as the requirements of stressed organs and tissue may increase. Hence, further supplementation may be beneficial under hypoxic stress for better adaptability. METHOD: Volunteers were divided into two groups: with and without zinc and copper salt supplementation. Blood samples were collected at sea level and on induction to acute hypoxia on days 3 and 10. Trace mineral contents and their related enzyme (alkaline phosphatase) and hormone (ceruloplasmin) levels were determined in plasma samples. RESULTS: Plasma zinc contents were significantly reduced upon induction to high altitude in the non-supplemented group, but not in the zinc-supplemented group. Alkaline phosphatase activity increased significantly upon induction to the high altitude stress. The enzyme activity remained elevated up to day 10 of the stress. Plasma copper contents and ceruloplasmin activity did not change upon induction to high altitude. CONCLUSION: Under hypoxic stress, circulating levels of zinc and alkaline phosphatase in plasma changed appreciably as plasma zinc was transported into the organs and tissues. However, circulating levels of copper and ceruloplasmin in plasma did not change, indicating no extra supplementation of copper is required under hypoxic stress.