Drugs & Behavior (Part 1-Lecture 1)

~ Key Terms ~

~ Extreme Key Terms ~

~ Bonus ~

Routes of Admin Part 1

Routes of Admin Part 2

100

Studies ways in which drugs move through the body

Pharmacokenetics

100

Atropine is a competitive antagonist of muscarinic acetylcholine receptors. It causes Increased Heart Rate, Dry Mouth, Large pupils, Urinary Retention, Constipation, & Extreme Confusion.

What is the drug action, therapeutic effects, side effects, and drug effects in this case?

Drug action: Atropine

Drug effects: all of its causes

Therapeutic effects: Increased Heart Rate

Side effects: Dry Mouth, Large pupils, Urinary Retention, Constipation, & Extreme Confusion

100

What does ED50, TD50, LD50, and TI represent?

ED50: half of the maximal dose

TD50: half of the 100% toxic dose

LD50: half of the 100% lethal dose

TI: margin of safety

100

R-of-A: Oral (enternal "gut" administration)

Advantage and disadvantage?

Advantage: easy to administer

Disadvantage: first-past metabolism by the liver (some is metabolized before it reaches bloodstream)

Irregular blood plasma level influenced by metabolism slow onset

100

R-of-A: Intraperitoneal

Advantage /Disadvantage?

Advantage: useful in research, variable metabolism, absorption, and distribution but can be as fast as IV

Disadvantage: not common in humans, but used in research

200

Define ADME

Absorption

Distribution

Metabolism

Elimination

200

What is the MAIN difference between Therapeutic Effects and Side Effects?

In TE, the drug-receptor interaction produces DESIRED physical or behavioral effects

whereas,

in SE, all drugs effects OTHER THAN DESIRED changes

200

Why is the purple line more potent?

Purple is more potent because it takes a lower concentration to have the same effect as green.

Rightward Shift = More Potent

200

R-of-A: Rectal (enteral "gut" administration)

Advantage and Disadvantage?

Advantage: Convenient if subject is vomiting, bypasses first pass metabolism

Disadvantage: less pleasant than oral, irregular blood plasma level, onset is difficult to predict

200

R-of-A: Intravenous

Advantage /Disadvantage?

Advantage: little to no initial metabolism, very quick distribution and onset

Disadvantage: difficult to administer, risk of infection, overdose, and is difficult to reverse

300

What is Pharmacodynamics?

A study which explains how the drug interacts with the target site

300

What is the definition of Half-life and what is its formula?

Hint: WE use this to determine dosing for drugs that exhibit first-order kinetics (non-saturable elimination).

The amount of time it takes to eliminate half of a dose of the drug from the body.

t_1/2= (0.7 x V_D)/ CL

-V_D is the drugs volume of distribution V_D = L/kg

-CL is the (constant) clearance of the drug CL = (L/h)/kg

300

What is a ligand?

What is an example of a biological ligand and a mimic of that ligand?

Biological ligand – Norepinephrine

Mimic - Clonidine

Lock & Key Fit & Mimics :

300

R-of-A: Transdermal (nicotine patches)

Advantage and Disadvantage?

Advantage: easy to administer, bypasses first metabolism, controlled and sustained delivery, influenced by blood supply to site of administration

Disadvantage: can irritate the skin

300

R-of-A: Inhalation

Advantage /Disadvantage?

Advantage: easy to administer, no initial metabolism, very quick (seconds), lungs are rich in capillaries and the blood that leaves the lungs goes straight to the brain

Disadvantage: might irritate nasal passages and damages lungs

400

The specific molecular changes produced by a drug when it binds to a particular target site

Drug Action

400

What is the difference between Antagonist & Agonist drugs effects?

Antagonist drugs have compounds that interfere with or inhibits the physiological action or another

whereas,

Agonist drugs have compounds that bind to a receptor and activate the receptor to produce a biological response

400

How does lipid-soluble drugs move across the cell membrane?

Passive diffusion

Lipid soluble drugs move from higher to lower concentrations called a concentration gradient

400

R-of-A: Intramuscular

Advantage /Disadvantage?

Advantage: can self-administer (epipens), destroy at site or by lymph, slow, even absorption over time ~ 10 to 30 mins.

can adjust using oil or coinjections, influenced by blood supply

Disadvantage: Less convenient than transdermal, can cause irritation and muscle discomfort

400

R-of-A: Topical

Advantage /Disadvantage?

Advantage:easy to administer (utilizes mucous membranes), bypasses first pass metabolism, can be quickly taken up by the blood, intranasal moves straight into the blood and bypasses blood brain barrier

Disadvantage: most drgus have a high molecular weight and are poorly lipid soluble, so they are not absorbed by the skin or mucous membranes

500

What is the difference between Specific Drug Effects and Non-Specific Drug Effects?

Specific drug effects focuses on the physical and biochemical interaction of a drug with its target sites, whereas Non-specific Drug Effect focuses on drug effects unique to the characteristics of the individual

500

What is the difference First & Zero order kinetics?

What is Half-life?

1st order: drugs are cleared from blood at an exponential rate

Zero order: clearance is at a constant rate regardless of drug concentration

e.g Alcohol; when you have more alcohol molecules than enzymes to break it down

Half-life is the amount of time it takes to clear 50% of the drug from the blood