pharmacokinetics

pharmacology

the chemical effect of drugs on the biological activity of the body

drug

used for treatment, prevention, diagnosis, or balance

active ingredients, adjuvants

what needs to be included in the drugs facts on a drug

adjuvants

the inactive ingredients in a drug. they add volume to the drug and assist in its breakdown or formation

types of active ingredients

glycosidic, alkaloids, microorganisms, minerals, from animals

glycosidic

consists of a mono or polysaccharide molecule attached to a non sugar

alkaloids

active ingredient that is more expensive and are used less. they contain Nitrogen, and are complex and difficult to make

semi-synthetic active materials

they come from a natural origin but they contain an additive, chemical change, or additional structure. these changes can make the drug more stable, increase its life-span, and help with its absorption

synthetic active materials

most of the new drugs are in this category. the lab will create multiple molecules, test them, and then use the most effective one

systemic and local

drugs can have two different types of effects on the body system:

systemic

the drug will reach its destination through the blood stream and will have an effect on the entire body.

local

these drugs need to be given to a specific place and will only have an effect on that specific location.

enteral and paraenteral

the two types of systemic drugs

enteral

anything that enters the body by way of the digestive system and then continues to the blood stream.

oral, sublingual, rectal

ways of administering enteral drugs

paraenteral

anything that enters the bloodstream directly, skipping the digestive system.

IV, IM, SC, transdermal, inhalation

ways of administering paraenteral drugs

aspiration

when administering an IM drug, what must be done before completing the injection

inhalation

this method of delivery can be used for a systemic or a local effect.

pharmacodynamics

the effect the drug has on the body

pharmacokinetics

the effect the body has on the drug

liberation, absorption, distribution, metabolism, excretion

the 5 phases of pharmacokinetics

liberation

שחרור

absorption

ספיגה

distribution

פיזור

metabolism

עיבוד

excretion

סילוק

breakdown and dissolving

the two phases of liberation

so that it can break down and dissolve in the digestive system

why do pills have additives in them that can absorb water

powder

capsules, unlike pills, dont have the ability to absorb water to take with them to the digestive system. Instead they have _____ inside

weak areas

capsules get broken down because they have _____ in which fluid can enter and force the capsule to open and powder to flow out

liquid drugs

these drugs don't have a liberation phase

absorption

absorption of the active ingredient and the time it takes for the drug to travel from the digestive system to the blood stream

simple diffusion, pinocytosis, הובלה ייחודית

ways absorption of a drug can occur

protein mediated transport, facilitated diffusion, active diffusion

סוגי הובלה ייחודית

simple diffusion

lipophilic and hydrophobic drugs can cross the membrane passively through this method of diffusion

fatty membrane

drugs have to be lipophilic to cross the digestive system because the digestive system has a _________

protein mediated transport

proteins that are perfect matches for a drug can act as a carrier for the drug through the digestive system

facilitated diffusion

דיפוזיה מסייעת

facilitated diffusion

transports molecules according to their current. there are also canals, תעלות, that help transport the drugs as well

active transport

transport of a substance across a cell membrane against the concentration gradient. it requires ATP

pinocytosis

a vesicle will separate from the digestive system membrane and swallow the drug

2

ph of the stomach. acids will be absorbed there

6

ph of the intestine. bases will be absorbed there

tissue surface area, blood flow, pH, full or empty stomach

absorption factors

greater

the _____ the tissue surface easier the better the drug will be absorbed

empty

drugs that get absorbed in the intestine should be taken on an ______ stomach so the drug gets there faster

full

drugs absorbed in the stomach should be taken on a _____ stomach, so that they have time to be properly absorbed

weak bases

most drugs are _____ and therefore it is better to take then on an empty stomach. 2 hours before or after eating

statins

help lower cholesterol levels in the body. they must be taken with food in order to help their absorption

Iron

should not be taken with milk, but vitamin c will help with absorption

antibiotics

should not be taken with dairy. and they must be taken at the same time each day so that the absorption rate will be the same every time

NSAIDs

need to be taken with food because the hurt the stomach lining

first pass effect

the amount of the drug that was broken down in the liver, or intestine, before the drug was released to the blood stream

bioavailability

זמינות ביולוגית

bioavailability

the ratio of the amount of drug that reaches the blood vs. how much drug was in the dose given

decrease

if the first pass effect increases, then bioavailability will ______

AUC oral

the area under the curve of the absorption curve that shows the total amount of drug given

AUC injected

the area under the absorption curve showing how much of the drug reached the blood stream via injection

bioavailability

(AUC oral/ AUC injected ) x 100

bioequivalence

when a generic drug has the same bioavailability as a brand name drug. this allows it to skip all the clinical trials the original drug had to undergo

Tmax

the time at which the concentration of the drug in the blood is at its highest

Cmax

the amount of drug that has been absorbed into the bloodstream when its concentration is the highest

original drug

a drug that was created by a drug manufacturer that they have a patent on. other companies are not allowed to create this drug

generic drug

a copy of the original drug that has the same active ingredients at the same concentration, bioequivalence, but it has different additives

distribution

the 3rd phase of pharmacokinetics. the drug is transferred from the blood to the tissues by dissolving or attaching to proteins

free drug

only this version of the drug will be absorbed by the tissue and will be considered to have an active effect

lipophilic

molecules that connect to fats and proteins and don't dissolve into the tissue

1%

how much of a lipophilic drug will be dissolved into the tissue as a free drug

hydrophilic drugs

will dissolve into the tissue and be fully absorbed

albumin, alpha 1 acid glycoprotein

the two main protein transporters of drugs

displacement

occurs when two drugs have attraction to the same protein. the one with a higher attraction will connect to the protein, while the second drug will be left in its free form and a higher percentage of it will be absorbed into the blood stream

causes of low albumin levels

אי ספיקת כליות, תת תזונה, כוויות, מחלות כבד

dehydration

main cause of high albumin levels

inflammation

main cause of high alpha 1 acid glycoprotein levels

onset, duration, intensity

דברים המשפיעים על דיפוזיה של התרופה מהדם אל רקמות השונות

volume of distribution

amount of drug/concentration of drug נפח הפיזור

volume of distribution

the volume of the plasma needed if all of the medication was absorbed into the blood. this tells us how much medication stayed in the blood vs. how much left to somewhere else

less

נפח פיזור יותר גדול אומר שלתרופה היה _____ זיקה לחלבון, וההפך

increase

the more a drug is lipophilic the more the volume of distribution will ______

tight junctions

connections between endothelial cells in the brain that only allows the passage of small lipophilic molecules during diffusion

metabolism

chemical changes that occur to molecules in order to make them more hydrophilic. it mainly occurs in the liver

prodrug

drug is inactive before metabolism and is active after

active drug

drug takes effect directly without need for metabolism

prodrug

5% of all drugs. It is used to fix absorption and distribution issues, and to cause the drug to only work in a specific area, or to allow it to pass through the BBB

Phase 1

phase of metabolism that is a compilation of reactions to turn the drug ore hydrophilic

CYP 450

a group of enzymes that help with the oxidation of drugs

overactivity of CYP

there will be an increase in speed of excretion of the drug from the blood and a decrease in drug activity

underactivity of CYP

there will be a decrease in speed of excretion of the drug from the blood and an increase in drug activity

grapefruit juice

blocks the activity of many different types of CYP enzymes

conjugation

the 2nd phase of metabolism. a chemical connection is made between the metabolite and the water soluble materials in the body

excretion

last phase of pharmacokinetics. it mainly occurs in the kidney

clearance

the ability of organs to remove a drug from the bloodstream

half-life

the time it takes for a drug to decrease to half of its original concentration in the blood. this is a set amount of time for the drug not effected by how much of the drug was taken (unless it was an overdose)

first order kinetics

the more substrate there is in the blood stream the faster the enzyme will work to break it down. Here half-life is fixed

zero order kinetics

when the enzyme clearing the drug from the bloodstream reaches its maximum speed and plateaus. the rate of clearance will decrease causing half-life to increase because the enzyme can no longer excrete it at a constant rate

4-5

after how many half-lives will the medication be completely excreted from the body

diazepam

this drug has an active metabolism and a 200 hour half life. alcohol cannot be taken with this drug and because of how long it's half life is, no alcohol is allowed for a month following taking this drug.

steady state

A plateau when the amount of drug absorbed is equal to the amount being excreted. It is achieved when a drug is given continuously through an IV

every t1/2

when the drug is given intermittently there are spikes in the curve before the meds reach SS levels. It will take 4-5 t1/2 to reach SS if the drug is given _______