ACUTE TOXICITY OF FOUR DRUGS IN HIGH ALTITUDE AND HYPOBARIC CONDITIONS

The total flavone glycoside of Oxytropis falcata, benadryl, sodium pentobarbital and aminophylline were studied in high altitude and hypobaric conditions to assess the acute toxicity in mice. It was found a tendency that the toxicity was increased with altitude. But the difference was insignificant in 2270 m compared with sea level. While the altitude "rose" from 3500 to 7000 m a significant increase of the acute toxicity occurred accor-ding to the feature of drugs themselves. The aminophylline was more toxic with altit-udes, in 3500 m the dosage of LD₅₀ decreased 14.5%, decreased 20.2% and 28.5% in 5000 m and 7000 m respectively. The degree of decreased LD₅₀ with altitudes was in the order of aminophylline, sodium pentobarbital, benadryl and the total flavone glyco-side of Oxytropis falcata. It is thought that hypoxia can be one of the factors to inf-luence acute toxicity of drugs; thus, enhanced toxicity may be attendant to high altitude medicine.