Pharmacology Exam I part 2

octanl; water partitioning coefficent that tels you how lipid soluble a chemical is, the drug is added to water and octanol and is then measured to see how much is in the water or octanol phase

a surrogate for fat

drug is water soluble

the drug is lipid soluble

log KOW of 1-4; most drugs are not lipid soluble because if it was lipid soluble then it would go to the fat which is distributed to the whole body

• pH 1 log KOW: 3-4
• pH 7 log KOW: <1

lipid solubility fo the drugs

the amount of drugs that reaches blood stream; ex. propanolol ~20% Bioavailable dose of propanol

route that most drugs take; some drugs are so small they can diffuse through nuclear pores such as ethanol

pH 1 then 99.9% of it is neutral/nonionized form so it will absorb easily in acidic environment (stomach)

does not take long because doesn't need to diffuse 100% of what is inhaled goes into the body

most drugs can't penetrate into the blood by the skin

EDTA or co-solvents can increase absorption

GI motility (are you eating? is your stomach active?), blood flow, and gastric emptying

you take a drug and then you eat something, the food will push the drug to the small intestine therefore the drug won't work

the intestines contain many folds (everyone has different number of folds in the intestine)

to prevent ulcers

measure of how widely distributed a drug is in the body. this measure tells us where the drug goes

dose/[] in plasma ; we usually don't want a drug to distribute all over the body

plasma proteins (esp. albumin protein), liver and kidney, bone, fat and hydrophobic components

increases the residence time in plasma

goes to the liver and tissues

absorption, distribution, metabolism, and excretion

recieves 25% of CO and some drugs can be actively secreted into glomerulus into tubules

biliary excretion

when the drug goes from the large intestine back to the liver through the portal vein

drug being reabsorbed in liver (ex. birth control drug); we are not able to control it but it is important to be aware of it

the smaller the VOD the better. usually durgs are less than or equal to 3 are good. if the VOD value is closer to the value fo the plasma concentration the drug is more effective

heparin and insulin

diazepam (valium) and ethanol (vod of 40-50)

it is so small so it has the ability to travel through pores

blood flow and solubility

brain, liver, kidneys, lungs and heart

generally happens int he liver but many other tissues are also metabolic

detoxification and bioactivation

Phase I and Phase II

oxidation, reduction, hydrolysis; most drugs go through this phase to make it more reactive

conjugation enzymes; phase II is to make drugs more water soluble to be eliminated easily

alcohol dehydrogenase

superfamily (there are subgroups such as CYP450 1 and CYP450 2) of heme containing proteins; contained in the endoplasmic reticulum

increase

if they are taken together drug B will be metabolized faster so the therapeutic affects of it are shorter

decrease

if they are taken together then drug B cannot be metabolized which increases half life of body