Chapter 4: Psychopharmacology Flashcards
Psychopharmacology
Study of effects of drugs on nervous system and behavior
Drugs
Exogenous chemical not necessary for normal cellular functioning that significantly alters functions of certain cells of body when taken in relative low doses
Drug Effects
Observable changes in individual’s physiology and/ or behavior
Sites of Action
Location where drug molecules interact with molecules on or in cells to affect biochemical processes
Absorption
Drug is administered and absorbed through tissue
Distribution
Drug is distributed throughout blood and body
- Rate at which drug reaches sites of action is based on lipid solubility
Lipid Solubility
Ability of fat-based molecules to pass through cell membranes
Ex. Heroin is more lipid- soluble than morphine
Metabolism
Drug is changed to inactive form by enzymes (usually in liver)
Excretion
Drug is excreted in urine by kidneys
Intravenous (IV) Injection
Injection of substance directly into brain
Intraperitoneal (IP) Injection
Injection of substance into peritoneal cavity
Intramuscular (IM) Injection
Injection of substance into muscle
Subcutaneous (SC) Injection
Injection of substance into space beneath skin
Oral Administration
Administration of substance into mouth so that it is swallowed
Sublingual Administration
Administration of substance by placing in beneath tongue
Inhalation
Administration of vaporous substance into lungs
Topical Administration
Administration of substance directly onto skin or mucous membrane
Insufflation
Administration of substance by sniffing or snorting
- drug is absorbed through mucous membranes of nose
Dose Response Curve
Graph of magnitude of effect of drug as function of amount of drug administered
Therapeutic Index
Ratio between dose that produces desired effects in 50% of animals and dose that produces toxic effects in 50% of animals
Drugs vary in effectiveness because of:
- site of action
- affinity of drug with site of action
Drug Affinity
Readiness with which two molecules join together
- most desirable drug has high affinity for sites of action producing therapeutic effects and low affinity for sites of action producing toxic side effects
Opiates have more than one effect
- Analgesia
- Depress heart rate and respiration
Tolerance
Decrease in effectiveness of drug that is administered repeatedly