Pharmacology General Principles Flashcards
What is Pharmacology?
The study of substances that interact with biological system through chemical processes
What are drugs?
substances (but not foods) that affect biologic function through chemical actions
Pharmacology is a_____ and ____ science
basic and clinical
What are the subdivisions of Pharmacology?
1) Pharmacotherapeutics
2) Pharmacokinetics
3) Pharmacodynamics
4) Toxicology
5) Pharmacogenomics
Define Pharmacotherapeutics
The diagnosis, treatment, and prevention of disease through the use of drugs
Define Pharmacokinetics
The qualitative and quantitative description of what happens to a drug in the body over time
“body affecting drug”
Define pharmacodynamics
The site and mechanism of action of the drug affecting the body
Define Toxicology
Adverse effects of drugs and environmental chemicals
Define Pharmacogenomics
The study of genetic variations that cause differences in drug response
Define Summation
The combination of two drugs with similar actions that produces an additive effect
Define Synergism
The presence of one drug enhancing the effects of another to produce effects greater than that of simple summation
Define Antagonism
The presence of a drug that block or reverses the effects of another
Define Latency
The delayed onset of therapeutic effects
Define Tolerance
Acquired insensitivity (requires at least one exposure
What are the two types of tolerance?
Tachyphylaxis (rapid) and slow
Define Drug resistance
lack of responsiveness to drugs
What cells often show drug resistance?
bacterial or cancer cells
Define drug sensitivity
Exaggerated response to a drug (genetic)
What are the 3 most important properties of an ideal drug?
Efficacy**
Safety
Selectivity
All drugs produce side effects and thus are not completely ________
selective
Define efficacy in relation to drugs
The ability to produce a specified reaction
Define safety in relation to drugs
A drug with minimal potential to cause injury even at high doses or when taken for an extended period of time
Define selectivity in relation to drugs
a drug which produces only the responses for which it is given; receptors are responsible for this
What happens in the 0-4 years of preclinical drug testing?
Drugs are identifies, tested in vitro and tested in animals
What portion of drug testing does the drug metabolism and safety assessment occur during?
animal testing, phase 1,2,and 3
What happens during phase 1 of drug testing?
- Identification of pharmacokinetic parameters (how does the body affect the drug? Is it safe?)
- 20-100 subjects
What happens during phase 2 of drug testing (~ 1 year)?
- It is given to people who have the disease to test for EFFICACY
- 100-200 patients
What happens during phase 3 of drug testing (~1 year)?
- multicenter
- 1000-6000 patients–> trying to catch a rare toxicity
- double blind to test the placebo effect
What happens during phase 4 of drug testing(~2 years)?
It is the postmarketing surveillance that may show toxicities or other effects of the drug once it is being prescribed.
When do you have to fill out the New Drug Application and get FDA approval?
between phase 3 and 4
What was the purpose of the Federal Pure Food and Drug Act of 1906?
It was a labeling law that prohibited misbranding and adulteration of foods and drugs
What is the purpose of the Food, Drug and Cosmetic Act of 1938?
It required that new drugs be “safe” but did NOT require proof of efficacy
What was the purpose of the Harris-Kefauver Amendment of 1962?
It required proof of efficacy
What is a category D drug for pregnancy risk?
There is evidence of human fetal risk, but potential benefits may outweigh risks
What is a category X drug for pregnancy risk?
Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk and the risks outweigh potential benefits
What is bioavailability?
The amount of drug reaching the blood in relation to how much is taken
1= all of the drug absorbed
What are the physiologic variable that affect drug responses?
body weight and size
age
gender
What are the pathologic variables that affect drug responses?
renal insufficiency
hepatic disease
acid/base imbalance
altered electrolyte status
What are the genetic variables that affect drug response?
variations in biotransformation
variations in functional proteins and enzymes
variation in receptor proteins
How does a drug become antigenic?
It must be covalently linked to a macromolecule (usually a hapten-protein complex)
T/F allergic reactions to drugs are unrelated to its pharmacological effect
True
