54 TROPICAL MEDICINE AND HYGIENE 



The form in which quinine is taken is of some import- 

 ance. The amount of anhydrous quinine in the various 

 salts differs, and the solubility of the salts also varies, as 

 shown in the subjoined table, which also shows the 

 doses of the common preparations of quinine equivalent 

 as regards the amount of quinine to 10 gr. of the 

 hydrochlorate. 



With a perfectly healthy stomach and a free secretion 

 of hydrochloric acid, all these salts will be converted into 

 the hydrochloride or bihydrochloride before they are 

 absorbed, so that in that case the varying amounts of 

 quinine only are of importance. 



When the stomach is not healthy or, as is so often the 

 case in malaria, the acid secretion is not normal, the 

 case is different, and at the best the quinine will be more 

 slowly absorbed, or at the worst only absorbed in small 

 part. The same occurs with an empty stomach as then 

 there is little or no acid secreted ; and for the same reason, 

 if the contents of the stomach do not excite gastric 

 secretion, as when they are mainly water or watery, 

 vegetable food solution and absorption of the less soluble 

 preparations of quinine will not be complete. 



The acid set free in the case of the sulphates will be 

 sulphuric acid, which is not of much value in the 

 digestive processes, and, acting as an astringent, may 

 increase the tendency already marked in malaria to 

 digestive disturbances. 



When the hydrobromide is used, and still more with 

 the bihydrobromide, the amount of bromine has to be 

 considered, as in 10 grains of bihydrobromide there is 

 bromide equivalent to about 3 gr. of potassium bromide. 

 Where this drug is used as a prophylactic for long 

 periods, mental depression may occur not only from the 

 quinine but also from the bromine. 



The hydrochloride contains a larger proportion, 8rS 

 per cent., of quinine; it is a little more expensive but not 

 sufficiently so to prevent its general use. It is more 

 soluble (i part in 40 of water) and less irritating. The 



