Exam 1 Overview Flashcards
Drug
Treats diseases.
Affects living processes.
Chemical component that affects life.
- Therapeutic Applications
Pharmacology
Study of drugs.
- Interactions w/ living systems.
Clinical Pharmacology
Study of drugs in humans.
- Use of drug to treat pts.
Therapeutics
How drugs treat disease.
Properties of an IDEAL Drug
Effective
- Has to do what it says to do.
- Executes proper responses for which it’s given.
*Most important property a drug can have.
Safety
- Doesn’t have harmful effects.
Selectivity
- Does what it’s supposed to do at the area it needs.
*Elicits only response for which it’s given.
What is the Therapeutic Objective of Drug Therapy?
Maximum benefit with minimum harm.
Administration
Drug dosage, route, and timing of administration.
Medication Errors: Administered by wrong route, wrong dose, and wrong time, or wrong drug.
Pharmacokinetics
Impact of the body on drugs.
- Getting to site of action.
Absorption (how body takes in meds.), Distribution (how drug is given out to the body), Metabolism (how med. is broken down), Excretion
Pharmacodynamics
Impact of drugs on the body.
- Nature and intensity of response.
- Drug-Receptor Interaction
- Placebo Effect: Think something has an effect when it does not.
Sources of Individual Variation
Determine pt’s response to a drug.
- Physiologic, Pathologic, and Genetic
Tailor drug therapy to every individual.
Over the Counter vs. Prescription
OTC
- Mild symptoms, more affordable, more likely to become addicted, don’t need doctor’s orders, some regulated by FDA
Prescription
- More side effects, more likely to cause drug interactions, more addicted, need doctor’s order, higher FDA regulations
Pharmacokinetics
Impact of body on drugs.
Absorption
Movement of drug from its site of administration into blood.
Distribution
Drug movement from blood to interstitial space of tissues and into cells.
Metabolism
Enzymatically: Alteration of drug structure, how it’s broken down.
Excretion
Movement of drugs out of the body.
Pharmacokinetic Processes
Fastest Way: Intravenously, directly into body, pumped straight into the body and heart.
- Absorbed by GI tract.
- Into blood.
- From blood to site of action.
- Metabolism: Liver and kidneys (filter + excrete).
*Alcoholics cannot produce bile or break down drugs, so Tylenol can build up and pt overdoses. - Out through urine.
Channels and Pores
Only the smallest drugs can pass through channels.
Transport Systems
Some meds. need transport proteins.
*PGP (P-Glycoprotein): Multidrug transporter protein.
- Liver: PGP transports drugs into bile.
- Kidney: PGP transports drugs to urine.
- Placenta: PGP transports drugs back to maternal blood away from fetus.
- Intestine: PGP transports drugs into intestinal lumen.
- Brain Capillaries: PGP transports drugs into blood, limiting access to the brain.
Direct Penetration
“Like dissolves like.”
Membranes are lipids, so drug must be lipid soluble.
Polar molecules and ions cannot penetrate membranes.
pH Dependent Ionization
Acids: Gives a hydrogen ion in basic media.
Bases: Gains a hydrogen ion in acidic media.
Ion Trapping or pH Partitioning
When pH of fluid on one side of membrane differs from pH of other side, drugs will accumulate where pH favors ionization.
Administration
Into blood.
Intensity: Amount of absorption.
Factors Affecting Drug Absorption
- Rate of Dissolution: Drugs must first dissolve to be absorbed.
- Surface Area: Larger surface area, faster absorption.
*Some meds. are weight-based, more surface area to cover, so they up the dosage on meds. to have an effect.
- Blood Flow: Drugs absorb more rapidly where blood flow is high.
- Lipid Solubility:
