Exam 1 - Ch.1 Introduction Flashcards
What are drugs classified by?
- origin/source
- action
- therapeutic use
- site of drug action
- chemical structure
- mechanism of action
- street name
Pharmacology
scientific study of drugs concerned with all info about the effects of drugs on living systems
Psychopharmacology
effects of drugs on behavior
Neuropharmacology
drug-induced changes in the functioning of cells in the nervous system
What 3 things affect the drug experience?
- pharmacological factors: chemical properties, drug dosage, route of administration
- characteristics of the drug user
- setting in which a drug is used
Pharmacokinetics
how the body absorbs, distributes, metabolizes and excretes drugs
Pharmacodynamics
biochemical and physiological effects of drugs and their mechanisms of action (what they do)
What are the routes of drug administration? What are the pros and cons of each?
- oral - self administered/easy, but it is broken down a lot before reaching target site
- intravenous - fastest, more likely to reach target site, but there’s not much time for intervention
- intramuscular - slow and even distribution, but can cause irritation at injection site
- subcutaneous - slow and prolonged, but absorption is variable depending on blood flow
- inhalation - rapid onset, but can cause irritation of nasal passages
- topical - easy to administer, but may be absorbed into general circulation
- transdermal - controlled and prolonged absorption, but can cause local irritation
- epidural - rapid effect on CNS by passing BBB, but is irreversible an requires a professional
What is bioavailability?
portion of original drug dose that reaches the site of action
What factors affect drug absorption?
- ability to pass through membranes (lipid solubility)
- form of drug administration
- conditions at site of absorption
What factors affect drug distribution?
- blood flow: increased blood flow receive drug shortly after absorption
- diffusibility: a more diffusible substance is more easily into
- solubility: ease with which a compound can be dissolved
What is the difference between typical capillaries and brain capillaries?
- typical capillaries have fenestrations that allow for a high volume of liquids and large molecules (pinocytosis) to pass through
- brain capillaries have tight junctions that block passage, and require energy to be passed, protecting the brain. Surrounded by astrocytes, which form the BBB
What are the two laws that elimination of drugs follows?
1 - zero order kinetics: rate of metabolization is independent of the concentration of the drug in the system (EX: alcohol)
2 - first-order kinetics: rate of metabolization is dependent on the concentration of the drug in the system
Half life
time that must pass for the amount of drug in the body to be cut in half (half of the drug has been metabolized)
Receptors
protein structures serving as substrates for NTs and drugs
Agonist
drugs that bind to the receptor and mimic the effect of a NT (morphine)
Antagonist
drugs that bind to the receptor and block and produce no cellular effect, but prevent agonist from binding to the site
What is the difference between a competitive antagonist and a non-competitive antagonist?
noncompetitive antagonists do not bind directly to the receptor site, they bind elsewhere and distort the shape of it
What is the dose-response curve?
describes the amount of biological or behavioral effect (response) for a given drug concentration (dose)
What are the two doses that can be read from a dose response curve?
- effective dose: dose at which a given percentage of individuals show a given effect of a drug
- lethal dose: dose of a drug at which death occurs
What are ED50 and LD50?
- the dose at which 50% of your subjects reach the desired result
- the dose at which 50% of your subjects die
Drug tolerance
repeated administration of a given dose of a drug often results in reduced response to the drug
Dispositional tolerance
an increase in the rate of metabolizing a drug as a result of chronic use
Pharmacodynamic tolerance
decreased behavioral effects of a drug
- acute - tolerance occurs quickly
- protracted - tolerance takes place after multiple uses
Behavioral tolerance
tolerance occurs in the same environment in which the drug was administered, but is not apparent or is reduced in a new environment
Cross tolerance
tolerance to drugs in the same family
State-dependent learning
information learned under the influence of a drug is best recalled when the individual is in that drug-induced state (also applies to psychological state)
