Basic pharmacology Flashcards
What are the three types of names a drug can have?
- Chemical Name
- Generic Name
- Trade Name
**4. Street name
What is a drug?
A substance consumed to get high or to treat a disorder.
Define Chemical Name
This would be the formal chemical jargon a chemist uses to identify what the molecule of the drug looks like.
Define Generic Name
When a drug becomes established it gains a shorter name. This new name contains conventions which are clues to the nature of the drug. (Stems) which are usually the last part of the drug.
Ex: fluOXETINE …oxetine= antidepressant
Define Trade Name
When a drug company discovers and patents a drug it sells it under a name unique to the company which no other drug company sells by after the patent is up.
Trade Name composition?
Excipients(other ingredients) + active ingredient = formulation
The trade name refers to the drugs formulation!
Define Street Name
Drugs sold on the street for recreational purposes have this name. The names vary via location but usually at least one is widely known.
What are dosages stated in?
Milligrams
What is more important when administrating a drug, concentration or amount given?
The concentration at which it reaches in the body is more important. You could give x amount to three people with varying body weights but the concentration it reaches in each person will be different Argo so will the effects of it.
Factors to consider when giving dosages?
Metabolic rate, body weight and body composition.
small organisms have a higher metabolic rate Argo need a higher dosage of a drug
Describe briefly what a dosage response curve is.
A graph with the x axis : dose, y-axis: effect. On it you want to have a dose so low there is no detectable effect, a dose so high that increasing it would show no effect and a dose inbetween. This will highlight the effect of a drug at a given dose. ( s-shaped)
Define ED50
Effective dose at which 50% of the pop are showing an effect from the drug.
Threshold
the dose producing the smallest measurable response.
LD50
The lethal dose required to kill half the pop. (TD50 is the same)
Do you want the ED to be lower or higher than the LD50?
You want it to be lower since that would mean you require a low dose to get the desired effect of the drug while staying away from lethal dosage areas.
What is the Therapeutic Index? (TI)
TI= LD/ED ….The higher the TI the safer the drug is! It shows the relationship of lethality and effectiveness.
Define Potency.
The difference between the ED of two drugs being compared.The dose required to get an effect. The lower the dose required, the more potent the drug.
Define Effectiveness.
differences in the max effect that a drug produces at a dosage lvl. When comparing two drugs given at the same dosage, the one with the higher effectiveness is the better of the two.
Define Primary Effect.
the effect desired when taking the drug.
Side effect.
any other effect the drug as aside from the primary.
Define Antagonism.
when one drug diminishes the effect of another.
How is antagonism viewed on a graph?
Two DRC’s are done.
1. drug alone
2. drug + another drug
If the DRC of the first one shifts to the right via adding another drug this indicates antagonism. (ED increases)
Define an additive effect.
If adding another drug to the main drug causes the DRC to shift to the left. (ED decreases)
Define Super additive effect/potentiation.
When drugs have an effect much greater than anticipated if their separate effects were simply just combined.
Define Hypersensitivity.
a response to a drug dose so low that it would have no effect on an average individual.
Define Hyperreactivity.
A reaction to a normal dose of the drug as though it was a large dose.
Define Hyporeactivity.
insensitivity to a normal dose of a drug
Define Idiosyncratic response.
unexpected drug response that is unique to an individual.
ex: taking aspirin and seeing things
Define Paradoxical response.
a drug response that is the opposite of the expected response.
ex: taking Valium and being hyperactive instead of relaxed.
What is pharmacokinetics?
how drugs move into, get around in and are eliminated from the body.
What are the three processes of pharmacokinetics?
- Absorption: how the drug enters.
- Distribution: where it goes.
- Elimination: how it leaves.
Sites of Action are?
areas affected by a drug.
Define what Routes of Administration means.
The method used to get a drug inside the body. (artificial: injection)
Parenteral Routes of administration??
administration through the skin via hollow needle and syringe.
Vehicle????
the liquid a drug is dissolved or suspended in before it can be injected. (since most drugs are a powder or crystalline state)
Saline is a?
Vehicle. NaCl and water. It matches body fluids in [ ] and does not irritate tissues like just water would!!
What is needed if a drug is not water soluble? What kind of Vehicle?
A vegetable oil vehicle. oil type. Lipid-soluble drugs are administered via oil which slows the rate of absorption, prolonging the effect for days.
Drugs+vehicle are injected = ??
A small bubble or bolus.
What are the routes of administration?
- Oral: not the best, drug can be destroyed via stomach acid.
- Parenteral: not in or through the digestive system
a. IV
b. IM
c. SC
d. Intraperitoneal: membrane covers the gut is injected. (animals)
e. Intracerebroventricular (icv): injected into ventricles of the brain. - Inhalation : insufflation (snorting)
What is a synthetic drug?
It is made entirely in the lab. (not natural)
Semi-synthetic
derived from a naturally occurring source but it is modified in a lab.
Depot Injection?
Highly lipid soluble drugs are dissolved in a viscous oil which is injected into muscle. Can last up to 4 weeks. It slowly diffuses into the body fluids.
Buccal Membrane (mucous membrane)
absorption of drug via orally first occurs here.
oral>rectum (intrarectal)
Olive oil partition coefficient ?
equal amounts of oil and water are placed in a beaker and a fixed amount of drug is added.Oil and water are than separated. [Drug] is measured in each. Drugs that are highly lipid soluble will be in the oil mostly.
Ion?
Ions are molecules with an electric charge. They have no lipid solubility. Ionized molecules cannot pass through membranes.
Transdermal administration
drugs absorbed via the skin passing through the epidermis. Only lipid soluble substances can pass through otherwise a exposed area is needed.
Highly lipid soluble substances tend to be absorbed in?
Fat. If it is absorbed in fat it will have NO effect. But over time it is slowly released into the blood stream.
Ion trapping?
Weak bases?
Weak base drugs get trapped in the fluid [ ] that is more basic, and weak bases will be [ ] in fluids on the more acidic side of the membrane.
Blood-brain barrier?
specialized cells of the CNS wrap around capillaries and block the pores which substances normally diffuse through. A solid lipid barrier that non lipid soluble substances have a hard time getting through.
Unprotected portions by the blood-brain barrier?
1.
2.
- Area postrema : induces vomiting and screens for toxins
2. Subfornical organ: detecs hormone lvls in the blood, especially those with regards to the balance of bodily fluids.
Placenta??
intermediate organ between the fetus and wall of uterus. Lipid soluble substances can cross with ease.
Small forms of elimination?
Sweat, saliva and feces.
Liver
function
toxic molecules are changed into less harmful substances to be filtered out later of the blood via kidneys
Metabolism
process of restructuring molecules
Metabolites
products of metabolism which are either more useful to the body or less toxic than they originally were.Sometimes they can be more active than the original drug. (THC ex) They are more likely to ionize and cannot be reabsorbed via nephron wall.
First pass metabolism?
drug absorbed via digestive system will pass through the LIVER before going anywhere else and will undergo a certain amount of metabolism.
Kidneys
function?
filtering system that physically removes certain substances from the blood!
acids are reabsorbed
bases are excreted
First order kinetics ?
as the drug concentration lowers so does the metabolism rate of it.
Zero order kinetics ?
the rate of metabolism / elimination remains the same throughout. (alcohol)
Factors altering drug metabolism? (5)
age, gender, species, past experiences and genetics.
Depression of enzyme system can occur when?
Two drugs that are metabolized by the same enzyme will compete for the enzyme. Sometimes the enzyme can be simply blocked by another drug as well.
Therapeutic window?
high high drug concentration = many side effects
low low drug concentration= no therapeutic effect
The range is a therapeutic window.
Time Course Graph??
Absorption- assumes while being absorbed liver and kidneys are not working (hypothetical)
Elimination- assumes instantaneous absorption(hypothetical)
resultant - realistic, has both an absorption phase and an excretion phase.
Absorption phase with i.v.??
it is very steep, achieves high lvls and is metabolized quickly.
Absorption rate for oral administration?
absorption is slow, blood lvls do not reach the same as i.v. would but it lasts much longer in the body.
i.m. and s.c. absorption rates?
In the middle between the other two extremes. ie: i.v. and orally
