Adventures of Oral Drug - 2

After Liver - The drug molecules that escape various metabolism then get dispersed by blood circulation throughout the body. These molecules reach various parts of the system via blood vessels, and then diffuse into different organs.

Molecules of metabolized drugs are excreted out of the body via the kidneys and through the bile.  Even the drug which is not metabolized also can get excreted out of the body.  Interestingly, some of the drug might be re-joined to the blood circulation after filtration by the kidneys without going into the urine. 

The purpose of drug metabolism is to convert drugs into easily removable forms.

Drug molecules concentrate in the liver and kidneys since these organs are employed with drug removal. As a result harmful effects of drugs are often experienced in these organs.  This can be highlighted by the fact that most often drugs which are withdrawn from the market have liver toxicity problems or kidney failure problem.

Now I hope everyone should has become familiar with ADME (pharmacokinetics). Let me do a re-cap; - What actually is pharmacokinetics? - In simple terms, what body does to the drug after its administration is pharmacokinetics.  ADME stands for Absorption, Distribution, Metabolism and Excretion. 

Please note that 'E' does not stand for Elimination.  Metabolism and Excretion together constitutes Elimination.