ELIMIJ^ATION OF DRUGS 5 



(1) to delayed followed by rapid absorption from the aliment- 

 ary canal ; or (2) to slow — or sudden arrest of — elimination. 

 The salts of lead, mercury and arsenical preparations are 

 eliminated slowly. Digitalis and strychnine are said to be 

 especially prone to produce a cumulative action. Strych- 

 nine may, however, be given subcutaneously in gradually 

 increasing doses without the likelihood of poisoning. Digi- 

 talis may cause a cumulative effect in being slowly oxidized 

 in the body or in leading to contraction of the renal vessels 

 and suppression of urine-elimination. The drugs likely to 

 cause a cumulative action must be administered infrequently, 

 once, twice, or thrice daily ; whereas medicines which are 

 rapidly decomposed and eliminated (alcohol, nitrites, etc.) 

 may be given at very frequent intervals if desirable. The 

 term excretion is often used synonymously with elimination, 

 but, strictly speaking, a drug is not eliminated unless it has 

 been first absorbed. On the other hand, an insoluble drug 

 passing unabsorbed through the alimentary canal is said 

 properly to be excreted in the faeces. 



