Cano content L1-5 Flashcards
Define Hit
Primary active compound with non-promiscuous binding properties, exerting a certain threshold value in a particular assay
Define validated hit
Characteristic authentic sample of a hit compound with confirmed in a multi-point activity determination
Define lead
Prototypical chemical structure demonstrating activity and selectivity in a pharmacological or biochemically relevant screen
What is pharmacokinetics
How does the body interact with the drug
What do the letters in ADME stand for
Absorption
Distribution
Metabolism
Excretion
What is pharmacodynamics
How does the drug interact with the body
Describe absorption
Passage of the drug from its site of admission into the general circulatory system after enteral administration
How do drugs administered orally get absorbed
Drugs administered orally must be absorbed through the lining of the stomach or intestines to reach the blood supply
What is a barrier which may prevent of absorption
cell membrane of epithelial cells lining the GI track
Describe the cell membrane
The cell membrane is a phospholipid bilayer which acts as a hydrophobic barrier to the passage of water, ions and polar molecules
Describe what a drug must be to be absorbed
Lipid soluble
Water soluble
Therefore, the main structural properties of a drug governing its good absorption from the GI tract are its aqueous solubility and the balance between its polar (hydrophilic) and non-polar (hydrophobic) groups
What is drug bioavailability
Drug bioavailability is the fraction of a drug that is successfully absorbed into the systemic circulation
Outline what distribution is
Transport of the drug from its initial point of administration or absorption to its site of action. The main route is through the circulation of the blood. Once in the blood stream, distribution of a compound is rapid
What are drugs transported as
Drugs are transported as either a solution of drug molecules or bound to the serum proteins (i.e. albumins)
Describe how drugs are distributed around the blood supply
Via arteries, veins and capillaries
The drug is rapidly distributed throughout the blood supply but not evenly around the body
Describe how drugs are distributed to tissues
Drugs are rapidly distributed to tissues and organs since they can freely pass through pores in the capillary walls to reach surrounding aqueous fluids
Describe how drugs are distributed to cells
Many drugs have to enter the individual cells of tissues since their molecular target is contained within
So drugs need to be hydrophobic enough to pass through the cell membrane
Describe how drugs are distributed through the blood-brain barrier
The drug must pass through an endothelial cell, cross the cell and exit by passing across a second membrane
Difficult for polar substances
Describe metabolism in terms of drugs
Biotransformation of the drug in the body so they can be eliminated more easily.
chemical alteration
Describe excretion
Process by which unwanted substances are removed from the body
Describe excretion/elimination in the lungs
some inhaled compounds are exhaled without being absorbed
Describe excretion/elimination in the kidneys
renal excretion as urine
some toxins are reabsorbed usually by passive mechanisms
Describe excretion/elimination in the liver
Liver hepatic excretion as bile
More than 200 foreign compounds have been detected in bile
What are the minor routes of excretion/elimination
Breast milk, saliva, sweat