Physico-Chemical Properties and Drug Action

What are the different places a drug can go to once it distributes within the blood?

• liver (metabolism)

• kidney (excretion)

• site of action

• CNS

ADME stands for:

Absorption

Distribution

Metabolism

Excretion

What 2 processes does a drug have to go through when given orally?

1. dissolution

   • into aqueous environment of GIT

2. crossing the bio membrane

   • to reach the blood stream

   • requires lipophilic properties

What plasma protein mainly helps the lipophilic drug form a water soluble complex to allow for passage through the blood?

albumins

T/F: bio membranes are mainly lipophilic

TRUE

A drug that is very lipophilic with have ____ absorption but ___ dissolution.

good, poor

What functional groups increase the polarity and dissolution of drugs?

• very polar groups

  • hydroxyl groups

    • alcoholic hydroxyl (aliphatic)

    • phenolic hydroxyl (aromatic)

  • aliphatic amines → ONLY primary + secondary

  • COOH, amides, imides, CN, NO2, sulfonamides

What are functional groups that increase the lipophilicity of drugs?

• alkyl groups

• phenyl groups

• halogen groups (I >Br >Cl>F)

• ester: more carbons = higher lipophilicity