Unit 3 Summary
STUDY GUIDE for Exam 1
UNIT 1
Absorption
o The movement of the drug into the bloodstream after administration.
o About 80% of drugs are taken by mouth (drugs in solid form with disintegrate into small
particles and combine with a liquid to form a solution, this is a process known as
dissolution)
Factors influencing
o Blood flow
o Pain
o Stress
o Hunger
o Fasting
o Food
o pH
First pass effect
o After absorption of oral drugs from the GI tract, they pass from the intestinal lumen
to the liver via the portal vein. In the liver, some drugs are metabolized to an inactive
form and are excreted, thus reducing the amount of active drug available to exert a
pharmacologic effect.
Bioavailability
o Percentage of administered drug available for activity
Drug Distribution
o The movement of the drug from the circulation to body tissues
Factors influencing
1. Vascular Permeability and Permeability of cell membranes
2. Regional blood flow and pH
3. Cardiac output
4. Tissue perfusion
5. Ability of the drug to bind tissue and plasma proteins
6. The drugs lipid solubility
Protein binding
o As drugs are distributed in the plasma, many bind with plasma proteins
Albumin
Lipoproteins
AGP
o Drugs that are more than 90% bound to protein are known as highly protein bound
drugs (Warfarin, Sertraline, Glyburide, Furosemide & Diazepam)
o Drugs that are less than 10%bound to protein are weakly protein bound drugs
(Gentamicin, Metformin, Metoprolol, Lisinopril)
o The portion of the drug bound to protein is inactive because it is not available to
interact with tissue receptors and therefore is unable to exert a pharmacologic
effect.
, Unit 3 Summary
Labs to monitor
o Protein and Albumin levels
Free drug
o Portion of the drug that remains unbound is free, active drug.
o Able to exit blood vessels and reach their site of action, causing a pharmacologic
response.
Drug Metabolism
o Process by which the body chemically changes drugs into a form that can be excreted.
o The liver is the primary site of Metabolism.
Half-life
o The time it takes for the amount of drug in the body to be reduced by half.
Loading dose
o Used in the case of drugs with long half-lives (ex: Phenytoin)
o By giving a large initial dose (Loading Dose), that is significantly higher than
maintenance dosing, therapeutic effects can be obtained while a steady state is
reached.
Drug Excretion
o Elimination of drugs from the body
Routes
o MAIN ROUTE is through the Kidneys
o Bile
o Lungs
o Saliva
o Sweat
o Breast Milk
Labs to monitor
o Monitor Kidney Function
o BUN and Creatinine
o May run CMP’s and BMP’s to assess (eGFR) levels
Onset, peak, duration of meds
o Onset: The time it takes for a drug to reach the minimum effective concentration after
administration.
o Peak: When a drug reaches its highest concentration in the blood.
o Duration: The length of time the drug exerts a therapeutic effect.
Therapeutic drug monitoring
Peak levels
o Highest plasma concentration of drug at a specific time and it indicates the rate
of drug absorption.
o If the peak is too low, effective concentration has not been reached.
o Oral drugs peak times are usually 2-3 hours after administration
o IV drugs peak time is usually 30-60 minutes after the infusion is complete
Trough levels
STUDY GUIDE for Exam 1
UNIT 1
Absorption
o The movement of the drug into the bloodstream after administration.
o About 80% of drugs are taken by mouth (drugs in solid form with disintegrate into small
particles and combine with a liquid to form a solution, this is a process known as
dissolution)
Factors influencing
o Blood flow
o Pain
o Stress
o Hunger
o Fasting
o Food
o pH
First pass effect
o After absorption of oral drugs from the GI tract, they pass from the intestinal lumen
to the liver via the portal vein. In the liver, some drugs are metabolized to an inactive
form and are excreted, thus reducing the amount of active drug available to exert a
pharmacologic effect.
Bioavailability
o Percentage of administered drug available for activity
Drug Distribution
o The movement of the drug from the circulation to body tissues
Factors influencing
1. Vascular Permeability and Permeability of cell membranes
2. Regional blood flow and pH
3. Cardiac output
4. Tissue perfusion
5. Ability of the drug to bind tissue and plasma proteins
6. The drugs lipid solubility
Protein binding
o As drugs are distributed in the plasma, many bind with plasma proteins
Albumin
Lipoproteins
AGP
o Drugs that are more than 90% bound to protein are known as highly protein bound
drugs (Warfarin, Sertraline, Glyburide, Furosemide & Diazepam)
o Drugs that are less than 10%bound to protein are weakly protein bound drugs
(Gentamicin, Metformin, Metoprolol, Lisinopril)
o The portion of the drug bound to protein is inactive because it is not available to
interact with tissue receptors and therefore is unable to exert a pharmacologic
effect.
, Unit 3 Summary
Labs to monitor
o Protein and Albumin levels
Free drug
o Portion of the drug that remains unbound is free, active drug.
o Able to exit blood vessels and reach their site of action, causing a pharmacologic
response.
Drug Metabolism
o Process by which the body chemically changes drugs into a form that can be excreted.
o The liver is the primary site of Metabolism.
Half-life
o The time it takes for the amount of drug in the body to be reduced by half.
Loading dose
o Used in the case of drugs with long half-lives (ex: Phenytoin)
o By giving a large initial dose (Loading Dose), that is significantly higher than
maintenance dosing, therapeutic effects can be obtained while a steady state is
reached.
Drug Excretion
o Elimination of drugs from the body
Routes
o MAIN ROUTE is through the Kidneys
o Bile
o Lungs
o Saliva
o Sweat
o Breast Milk
Labs to monitor
o Monitor Kidney Function
o BUN and Creatinine
o May run CMP’s and BMP’s to assess (eGFR) levels
Onset, peak, duration of meds
o Onset: The time it takes for a drug to reach the minimum effective concentration after
administration.
o Peak: When a drug reaches its highest concentration in the blood.
o Duration: The length of time the drug exerts a therapeutic effect.
Therapeutic drug monitoring
Peak levels
o Highest plasma concentration of drug at a specific time and it indicates the rate
of drug absorption.
o If the peak is too low, effective concentration has not been reached.
o Oral drugs peak times are usually 2-3 hours after administration
o IV drugs peak time is usually 30-60 minutes after the infusion is complete
Trough levels
