COCAINE 187 



the dose employed. Small doses lessen the pulse rate, through stimu- 

 lation of the vagus. Blood pressure is rapidly raised by stimula- 

 tion of the vasomotor center, but this increased pressure is followed 

 by a temporary fall. Moderate doses accelerate the heart, largely by 

 depression of the vagus, both centrally and peripherally, together with 

 some stimulation of the accelerator mechanism. Blood pressure is 

 (juickly raised on account of the action upon the heart and also on 

 account of stimulation of the vasomotor center. The increased pres- 

 siire may be so great in some cases as to demand treatment. Large 

 doses give a very low blood pressure with a slow weak pulse, due to 

 depression of the medullary centers. Occasionally an unexplained, 

 almost instant collapse results in human patients after absorption, no 

 matter how given. 



Its local application constricts the bloodvessels. 



Respiratory System. The respiratory center in the medulla is 

 stimulated, causing an increased rate, with little or no change in the 

 depth at first. Later the stimulation gives way to depression, and 

 with large doses the respirations become shallow, while the rate may 

 be increased still further. If convulsions result, the respiration is 

 arrested, and, as after strychnine convulsions, may fail to be rein- 

 stated, or there may be a gradual respiratory failure. 



Nervous System. Moderate doses strongly stimulate the higher 

 parts of the brain and in the htiman family cause a sense of calm and 

 happiness. The centers are stimulated in the same general order in 

 which they are depressed by morphine, but the motor areas which are 

 not depressed by morphine are actively stimulated by cocaine; this 

 resiilts in circus movements in some animals. The stimulation is 

 followed by depression of the same areas, but the stimulation and 

 depression are not at all uniform, so that one usually sees evidence of 

 mixed stimulation and depression of the various centers during 

 cocaine poisoning. Animals have greater endurance and the in- 

 creased physical energy renders possible the performance of long 

 exhausting muscular feats. This is probably the reason that cocaine 

 is used as a stimulant (hop) in race horses. For the stimulant and 

 exhilarating effects, coca leaves are often mixed with clay or ashes and 

 chewed by the natives of Peru and the surrounding countries, but an 

 overindulgence leads to indigestion and extreme emaciation. Large 

 or toxic doses lead to depression, loss of coordination, narcosis and 

 cerebral convulsions. The sensory nerves are paralyzed and the 

 motor nerves depressed by toxic amounts. 



Eye. A two to four per cent, solution causes marked irritation 

 of the parts, together with a transitory contraction of the pupil, but 

 this is soon followed by anesthesia of the cornea and conjunctiva and 

 blanching of the mucous membrane. A few minutes later the pupil 

 dilates and remains so for one or two hours, but there is not a maxi- 



