Principle Of Pharmacology - Pharmadynamics Flashcards
Pharmodynamics
What the drugs do to the body
Pharmodynamics is the relationship between
drug concentration in the body and what the drug does to the body
Describe affinity (stickiness)
Affinity is the strength of a bond to a receptor site
Example: Fentanyl has a high affinity to opiate receptors
Who are receptors?
Protein target sites
What does the lock and key model describe?
It describes that drugs are selective and should only lock into the key receptor
What happens when there is a drug at high concentration in the body?
It loses its selectivity
What are the two possibilities of a drug action?
Agonist and antagonist reaction
Describe an agonist reaction
Triggers a response
Describe an antagonist reaction
No response triggered - drug occupies receptor site so that another drug can’t bind to it
Example: naloxone is used to block the effect of opioids or allergy medication
Onset
Time it takes for drug to elicit a therapeutic response
Peak
Time for drug to reach max therapeutic response
Trough
Lowest blood plasma conc.
Minimum effective concentration
Plasma drug level that must be reached for therapeutic effect
Duration
time for which a drug conc. is sufficient to elicit a therapeutic response
- therapeutic index
Measures drug safety
It is the area between amount at which drug is effective to amount at which drug the drug is toxic
