GALEN NUR 210 EXAM 1 MODULES 1-3 FULL
EXAM UPDATE
Pharmacokinetics
• The process in which medications move through the body
What are the 4 phases of pharmacokinetics?
• absorption, distribution, metabolism, excretion
Absorption
• happens with drug movement from the GI tract into the bloodstream. Most meds are taken by mouth.
Oral absorption
• Takes awhile to get absorbed because it has to go through the GI system
Usually takes 2-4 hours
•Enteric coated
aspirin - hard on stomach
can not crush pill
•Extended release
absorbed in the small intestine
IM absorption
• Absorbed 1-2 hours
IV absorption
• Absorbed 30-60 minutes
dissolution
• Dissolution happens when a po medication breaks down into particles, disintegrates, and dissolves to combine with liquid so
absorption from the GI tract into the bloodstream occurs.
Liquid medications are absorbed faster than solids. Food can interfere with the absorption of drugs.
Drugs that resist dissolution
• Parenteral medications (SL, eyedrops, inhalants, transdermal) do not pass through the GI tract.
Enteric coated medications are designed to resist disintegration until the pill reaches the small intestine. EC and sustained
release meds should not be crushed.
Factors that affect absorption
• •Lack of muscle and increased fat changes medicine absorption
•Food consumption - will change medicine potency (delayed)
•Stress - Exercise, medicine goes to muscle
•pH - Medicine is made for acidic environments
•Antacid changes absorption
•Taken alone so it doesn't change the action
Excipients
• Fillers and other substances that make up tablets as a pill is not 100% drug.
Sometimes an excipient enhances the absorption of a drug such as with PCN, which is not well absorbed from the GI tract.
Adding Na to PCN, which makes it penicillin sodium, will increase the absorption of PCN
first pass effect
, • •the oral drugs go to liver via portal vein where some of the drug becomes inactive
•Only happens with oral medications
delayed gastric emptying
• Food doesn't move like it should
Distribution
• refers to the movement of the drug from the circulation to body tissues
Factors affecting distribution
• -blood flow to tissues
-protein binding
-blood brain barrier
-drug's affinity to the tissue
protein binding
• Drugs bind with proteins in blood
Some drugs are highly protein bound and other are weakly protein bound
free drugs
• drugs not bound to protein
Drug Toxicity
• -Two highly protein bound drugs compete and one might accumulate and cause a toxicity
-it is important to know if you are administering highly protein bound medications and monitor albumin levels in patients with
liver or kidney disease.
-Some drugs that are highly protein bound include: Warfarin
Furosemide
Diazepam
Drug distribution and albumin
• -A decrease in albumin levels decrease the protein-binding sites, which means more of the free drug is circulated.
-This can be fatal with some meds.
-Free drugs are those not bound to protein, which means they are active in the body and cause a pharmacologic response.
-Older adults, malnourished individuals, and those with liver or kidney disease have low albumin levels.
Blood Brain Barrier (BBB)
• -The BBB protects the brain from most drugs.
-Some meds are able to cross the BBB such as benzodiazepines.
-Drugs can cross the placenta and cause spontaneous abortion or alter fetal growth and development.
Metabolism
• •Chemically changes drug to a form that can be excreted
•Liver primary site
half-life
• •the time it takes for the drug in the body to be reduced by half
Loading dose
• use of a higher dose than what is usually used for treatment to allow the drug to reach the critical concentration (therapeutic
level) sooner
•Blood thinner
•Antibiotic
Exceretion
• the removal of waste products from medications which is done mainly through the kidneys
Other routes for include lungs, sweat, saliva, and bile
Factors effecting excretion
EXAM UPDATE
Pharmacokinetics
• The process in which medications move through the body
What are the 4 phases of pharmacokinetics?
• absorption, distribution, metabolism, excretion
Absorption
• happens with drug movement from the GI tract into the bloodstream. Most meds are taken by mouth.
Oral absorption
• Takes awhile to get absorbed because it has to go through the GI system
Usually takes 2-4 hours
•Enteric coated
aspirin - hard on stomach
can not crush pill
•Extended release
absorbed in the small intestine
IM absorption
• Absorbed 1-2 hours
IV absorption
• Absorbed 30-60 minutes
dissolution
• Dissolution happens when a po medication breaks down into particles, disintegrates, and dissolves to combine with liquid so
absorption from the GI tract into the bloodstream occurs.
Liquid medications are absorbed faster than solids. Food can interfere with the absorption of drugs.
Drugs that resist dissolution
• Parenteral medications (SL, eyedrops, inhalants, transdermal) do not pass through the GI tract.
Enteric coated medications are designed to resist disintegration until the pill reaches the small intestine. EC and sustained
release meds should not be crushed.
Factors that affect absorption
• •Lack of muscle and increased fat changes medicine absorption
•Food consumption - will change medicine potency (delayed)
•Stress - Exercise, medicine goes to muscle
•pH - Medicine is made for acidic environments
•Antacid changes absorption
•Taken alone so it doesn't change the action
Excipients
• Fillers and other substances that make up tablets as a pill is not 100% drug.
Sometimes an excipient enhances the absorption of a drug such as with PCN, which is not well absorbed from the GI tract.
Adding Na to PCN, which makes it penicillin sodium, will increase the absorption of PCN
first pass effect
, • •the oral drugs go to liver via portal vein where some of the drug becomes inactive
•Only happens with oral medications
delayed gastric emptying
• Food doesn't move like it should
Distribution
• refers to the movement of the drug from the circulation to body tissues
Factors affecting distribution
• -blood flow to tissues
-protein binding
-blood brain barrier
-drug's affinity to the tissue
protein binding
• Drugs bind with proteins in blood
Some drugs are highly protein bound and other are weakly protein bound
free drugs
• drugs not bound to protein
Drug Toxicity
• -Two highly protein bound drugs compete and one might accumulate and cause a toxicity
-it is important to know if you are administering highly protein bound medications and monitor albumin levels in patients with
liver or kidney disease.
-Some drugs that are highly protein bound include: Warfarin
Furosemide
Diazepam
Drug distribution and albumin
• -A decrease in albumin levels decrease the protein-binding sites, which means more of the free drug is circulated.
-This can be fatal with some meds.
-Free drugs are those not bound to protein, which means they are active in the body and cause a pharmacologic response.
-Older adults, malnourished individuals, and those with liver or kidney disease have low albumin levels.
Blood Brain Barrier (BBB)
• -The BBB protects the brain from most drugs.
-Some meds are able to cross the BBB such as benzodiazepines.
-Drugs can cross the placenta and cause spontaneous abortion or alter fetal growth and development.
Metabolism
• •Chemically changes drug to a form that can be excreted
•Liver primary site
half-life
• •the time it takes for the drug in the body to be reduced by half
Loading dose
• use of a higher dose than what is usually used for treatment to allow the drug to reach the critical concentration (therapeutic
level) sooner
•Blood thinner
•Antibiotic
Exceretion
• the removal of waste products from medications which is done mainly through the kidneys
Other routes for include lungs, sweat, saliva, and bile
Factors effecting excretion
