Lecture 1 Flashcards
introduction to pharmacology (43 cards)
1
Q
What is pharmacology?
A
the study of drugs. from Greek words “pharmakon” = remedy, and “logos” = study
2
Q
What does the study of drugs include?
A
- route of administration (how its delivered).
- mechanism of action (how it works)
- therapeutic effects
- adverse effects
3
Q
How do we classify therapeutics?
A
- drugs: traditional drugs (ex. chemical agents)
- biologics: hormones, antibodies
- natural health products: vitamins, minerals etc
4
Q
Legislative bodies for drugs
A
- therapeutic products directorate - traditional drugs
- biologic and genetic therapies directorate - biologics
- natural health products directorate - health products
5
Q
What is a drug?
A
chemicals that produce a pharmacological effect. usually made up of many molecules of the chemical
6
Q
What are the 3 different type of drug names?
A
- chemical name: describes the chemical structure of the molecule
- generic name: unique name that identifies a drug, the most often used in pharmacology
- trade name: name assigned by drug company (can be confusing bc many companies make the same drug but have different names for it)
7
Q
Steps in the Approval of marketed drugs in Canada
A
- preclinical testing
- clinical testing application
- phase I clinical trial
- Phase II clinical trial
- Phase III clinical trial
- New drug submission (NDS) submitted to health canada
- Phase IV Clinical Trial
8
Q
Preclinical testing
A
- can take up to 6.5 yrs
done in cultured cells, living tissue, or experimental animals
evaluate biological effects, pharmacokinetics, toxicity
9
Q
clinical tral application
A
- details all pre-clinical data
- must be submitted to Health Canada prior to any human studies
10
Q
Phase I clinical trial
A
- ~ 1 yr
- 20 to 100 healthy volunteers
evaluate pharmacokinetics and pharmacodynamics
11
Q
Phase II clinical trial
A
- ~ 2 yrs
- 300 - 500 patients with target disorder
- effectiveness, side effects, dosing info gathered
12
Q
Phase III clinical trial
A
- ~ 4 yrs
- 500-5000 patients with target disorder
- effectiveness verified, long term side effects assessed
13
Q
NDS submitted to Health Canada
A
- report detailing effectiveness and safety
- includes pre-clinical and clinical data
- if approved a notice of compliance (NOC) and drug information number (DIN) are issues and are required to market the drug
14
Q
Phase IV
A
post marketing surveillance
15
Q
What is pharmacokinetics?
A
- what the body does to the drug
- includes: absorption, distribution, metabolism, and excretion
- add in picture
16
Q
Physiological barriers to drug transport
A
- intestinal villi: fr a barrier against ingested drugs, toxins, and nutrients
- tight junctions: which prevent molecules from passing between cells
- drug might have the right chemical properties to pass through these barriers
17
Q
What is the nucleus
A
contains genetic material like DNA
18
Q
what is the smooth endoplasmic reticulum
A
metabolizes drugs, carbs, and steroids
19
Q
what is the rough endoplasmic reticulum
A
synthesizes proteins
20
Q
what does the golgi apparatus do
A
processes and packages proteins and lipids
21
Q
what does the mitochondria do
A
produces ATP (cells source of energy)
22
Q
cell membrane
A
separates the intracellular and extracellular environments
23
Q
what is the cell membrane made up of?
A
- phospholipids with polar (water soluble) phosphate head and two fatty acid (lipid soluble) tails
- is a flexible bilayer that also contains proteins embedded in it
24
Q
3 ways that drugs cross the cell membrane?
A
- direct penetration of the cell membrane
- through ion channels and pores
- transport proteins
25
Direction penetration of the cell membrane
- drugs must be lipid soluble (lipophilic)
| - hydrophilic drugs cannot pass through
26
through ion channels and pores
- channels and pores are very small so only very small compounds (molecular weight <200) can pass through
- channels are selective
examples of shit that can go through: sodium, potassium, lithium (a drug used in the treatment of bipolar disorder)
27
Specific transport proteins
- carrier proteins
- uptake: move drugs from outside to inside the cell, important in mediating intestinal absorption, renal excretion and reaching target sites of action
- efflux: move drugs from inside to outside the cell, important for cell protection. are present in the intestine, placenta, kidney, and at the blood brain barrier
28
types of drug molecules
1. polar molecules
2. ions
3. quaternary ammonium compounds
4. ionizable molecules
5. lipophilic molecules
29
Polar molecules
- water soluble
- have an uneven distribution of electrical charge yet no net charge
- examples: water, glucose, antibiotic kanamycin (OH group s make it polar bc of the distribution of e-)
30
Ions
- atoms or molecules where total number of e is not equal to the total number of p
- have a +ve or -ve net charge
- bc of their charge they cannot directly pass through the cell membrane: v small ones pass through ion channels or pores
- ex: Na+, K+, Cl-, Li+
31
quaternary ammonium compounds
- have at least one nitrogen atom and overall positive charge at all times
- unable to cross cell mem bc of their charge
32
ionizable molecules
- can be charged or uncharged
- are weak acids or weak bases
- whether or not it carries a charge depends on the pH of the surrounding medium
33
weak acid + acidic medium (ex. stomach) =?
non-ionized
34
weak acid + alkaline medium (i.e small intestine) =
ionized
35
weak base + acidic medium =
ionized
36
weak base + alkaline medium =
non-ionized
37
lipophilic molecules
- are quite lipid soluble (unlike polar molecules, ions, qas, and charged ionizable molecules)
38
The impact of pH on drug movement
- only non-ionized drugs can directly penetrate the cell mem
- most drugs are weak bases and cross mems more easily in an alkaline medium
- weak base + acidic environment = no passing
- weak base + alkaline environment = pass
- weak acid + acidic environment = pass
- weak acid + alkaline environment - no passing
39
when does Ion trapping occur
when there is a difference in pH on different sides of a mem
40
drug accumulation and ion trapping
- drugs accumulate on the side of the mem where they are ionized
ex. acidic drug in acidic environment in unionized and can pass through the cell membrane, but become ionized once they reach the other, more basic side and become trapped bc they can no longer pass through
41
Capillaries
- smallest blood vessel in the body
- supply tissue with oxygenated blood and allow the drugs and other molecules to move from the blood to the tissue (ex. lung and kidneys have rich capillary beds)
- heart --> arteries --> arterioles --> capillaries
42
drug movement out of capillaries
- have large gaps between them called fenestrations
hydrophilic drugs can pass between fenestrations to leave blood
- lipophilic drugs can pass between fenestrations or directly through the plasma membrane of capillary endothelial cells
43
drug movement out of brain capillaries
- blood brain barrier have tight junctions, not fenestrations
- drugs must be either lipophilic or have specific transport proteins to carry them into the brain
