Pharmacodynamics Flashcards
Pharmacodynamics is?
What the drug (chemical) does to the body
Drugs work in what 4 ways?
1) Replace missing chemicals
2) Stimulate particular cells
3) Slow down or inhibit cells
4) Interfere with foreign cells
Drugs exert their effects on the body by binding to what 4 various proteins?
1) receptors
2) enzymes
3) ion channels
4) carrier ( transporter ) molecules
What is a protein receptor?
A substance that fits precisely and can interact with it ( key and lock )
What is affinity?
The interaction between the drug and the binding site
What is specificity?
Combining with one particular receptor
What is an agonist drug?
Mimics
What is an antagonist drug?
Blocks
What is a competitive antagonist?
Competes with the agonist for the binding site
What is a non-competitive antagonist?
Binds to a site other than the agonist binding site
What is an alpha receptor?
Associated with mainly increased contractibility of vascular smooth muscle and intestinal relaxation
What is a beta-receptor?
Associated with vasodilation and relaxation of non intestinal smooth muscle and cardiac stimulation
Beta blockers are a class of drugs which work by blocking what?
Beta receptors
What effect would beta blockers have on cardiac muscle?
Reduces sympathetic influences on heart activity and makes the heart beat more slowly
What do NSAIDS ( non-steroidal anti inflammatory drugs ) block?
The activity of an enzyme by inhibiting the enzyme COX that is responsible for the formation of some important chemical mediators
What are Acetylcholinesterase inhibitors?
Used to improve or stabilise the symptoms of Alzheimer’s disease
Pharmacodynamics can be defined as
How the drug exerts it’s effects on the body
An antagonist for a receptor will block..
The receptor and inhibits the response of the endogenous ligand
A compete or enzyme inhibitor will?
Block the active site of an enzyme
Calcium channel blockers act as?
Vasodilator by blocking the intracellular calcium required for the contraction of arteriolar smooth muscle
Calcium channel blockers will?
1) lower blood pressure
2) slow the heart down
3) reduces the force of contraction in cardiac smooth muscle
Sodium channels block?
Sensation of pain
Channel blocks prevents the sensation of pain by blocking nerve impulses, how?
Inhibiting sodium influx through sodium channels in the nerve cell membrane
