CHAPTER X 

 CHEMOTHERAPY 



THE term chemotherapy introduced by Ehrlich is 

 used to describe the treatment of diseases due to 

 micro-organisms by m«ans of chemicals of known 

 composition. It is analagous to serotherapy which is 

 used for the treatment of such diseases by the use of 

 antibacterial or antitoxic sera. Rather curiously the 

 treatment of other conditions, such as the " deficiency " 

 diseases due to lack of vitamins, or of endocrinological 

 diseases, with drugs, even when their constitution is 

 known, is not included in the term chemotherapy. 



In recent years great advances have been made in 

 chemotherapy, particularly in that part of it dealing 

 with bacterial infections and it is now possible to account 

 for the mechanism of the processes on a fairly certain 

 basis . 



Chemotherapeutic substances cure by the destruc- 

 tion of the organism causing the disease. The action 

 may be directly on the organism or by stimulation of 

 the defence mechanism of the host or, frequently, by a 

 combination of both means. The organism may be 

 weakened, or otherwise rendered susceptible, so that the 

 tissue defences may be strong enough to overcome the 

 infection. 



The application of chemotherapy is obviously more 

 difficult in the case of a generalised infection, or in an 

 infection of a deep tissue, such as the central nervous 

 system, than when the infection is localised or readily 

 accessible to the action of the drug. In such conditions 



122 



