The study of relations of drug as is given at the end of each drug in Allen’s Keynotes is very useful. The study of their relations is very rewarding as can be seen from the following.
1. At the end of Abrotanum in the relationship it has been mentioned “After Acon and Bry in pleurisy, when a pressing sensation remains in affected side impending respiration.” On this indication I have used Abrotanum in two cases with success when Bry, relieved the pain but not completely and I was wondering what to do.
2. In the relationship of Aesculus. Hip following has been mentioned.
“After Coll. Has improved piles, Aesculus after cures.”
“Useful after Nux and Sulph have improved, but failed to cure piles.”
It is also useful to refer to Materia Medica when you have cured a particular case basing your prescription on certain keynotes, very often you know certain other symptoms of the drug which were present in the patient but you did not take note of.