We look we are high on cocaine, but really we are not, its just hypoxia from the lack of oxygen at that altitude.
Here is some more info;
Hypoxia is a state of oxygen deficiency in the body which is sufficient to cause an impairment of function. Hypoxia is caused by the reduction in partial pressure of oxygen, inadequate oxygen transport, or the inability of the tissues to use oxygen.
In brief, being drunk is kind of the same as being exposed to high altitude. In both cases, oxygen to your brain and muscles is reduced.