Exam 1: Intro to Pharm Flashcards
Pharmacotherapeutics
Therapeutic (medical) use of a drug
Diagnose, prevent, or treat disease
Six rights
Right drug
Right dose
Right patient
Right route
Right time
Right documentation
FDA Stages for Approval
- Preclinical investigation/testing (all in lab)
- Clinical investigation/testing (longest part)
Clinical investigation
Phase I: Normal (Healthy ) volunteers
Evaluation effects on humans & of drug metabolism
Phase II & III: tested on patients, determine therapeutic effects, dosage ranges, safety
Phase IV: Post marketing surveillance, used for gen. pop., new side effects reporting -> ADRs not found in stage 3
Properties of an Ideal Drug
“Maximum benefit with minimal harm!!”
Effectiveness - Elicits the response it is intended for
Safety - Causes no (or little) harm
Selectivity - Response limited for which it is given
also important:
Reversible action
Predictability
Easy to administer
Few drug interactions
Low cost
Chemically stable
Simple generic name
generic name vs trade/brand name
generic - official name given by manufacturer used in practice, sometimes ending of name can indicate drug classification (-cillin: antibiotic)
trade/brand - most common name, pt might know
generic drug
Tend to be lower cost
Lower cost than “Brand name” drugs …. bc generic is produced after the patent ends for original producer
brand drug vs. generic drug
Both: must have same Active Ingredient
contain same dose of same drug
Concern with generics:
Different binders and fillers
May change absorption-rate and extent
May not work the same
Generic drugs must have FDA approval
Sources of drugs
Plants
Animals or humans: such as Hormones
Minerals or mineral products
Synthetic
Made in the laboratory with same molecular function as natural molecule
Recombinant DNA: fragment of DNA is inserted into DNA of another organisms
Legend
Any drug that requires a prescription
Over-the-counter (nonprescription)
Many Legend drugs are now being approved for OTC sale
Scheduled/ Controlled drugs
Any drug with the potential of being abused
Class I –V
Class I extremely high abuse potential, no accepted medical use (Heroin and LSD)
Class II-V progressively less, have acceptable use but also potential for abuse
1970 Controlled Substance Act
Drug classification
drugs w/ similar characteristics
Treatment: symptoms/illness/disease
(Antiemetic, Analgesic, Antihypertensives)
Similar effect on a body system
(Diuretics, Antacid)
Similar pathophysiology effect
(ACE Inhibitor, Beta Blocker)
Pharmacoceutic Phase
only PO meds
Disintegration (for tablets, capsules are already in solution)
Dissolution - dissolve into the GI fluid before absorption (rate of dissolution dictates rate of absorption)
enteric coatings**
Pharmacokinetic phase
ADME
- absorption
- distribution
- metabolism
- excretion
Three primary ways to cross a cell membranes
- Pass through channels or pores (Only very small ions such as potassium)
2.Pass with the aid of a transport system (Different transport mechanisms- P-Glycoprotein ex.) - Direct penetration of the membrane (Most common)
P-Glycoprotein:
multidrug transporter protein
transports wide variety out of cell so it can be eliminated
present in liver, kidneys, placenta, intestine, and capillaries of the brain
“like dissolves like”
Lipid soluble drugs (lipophilic) can directly penetrate (mostly lipid) cell membranes
Ion transport
Ions (net electric charge) cannot cross membrane
depend on the pH of the environment as to whether the drug is non-ionized and able to cross cell membrane or not
“I(on) can’t get in!” example
Absorption
drug enters the body, gets into blood
Distribution
drug moves from blood to site of action
determined by factors of blood flow to tissues/organs abscesses/tumors ex. of low blood flow
Metabolism
biotransformation
enzymatic alteration of drug structure
most occurs in liver
Normal route is drug absorbed -> goes to liver via portal vein -> just passes through -> then into systemic circ -> after targeted effect -> returns to liver to be metabolized
Excretion
exits and is removed from body
Enteral vs parenteral
enteral - GI - PO & feeding tubes
parenteral - “by injection” IV, SQ, IM
Oral route
multiple preparations - have fillers & binders that allow for better dissolution and absorption
convenient & safe
absorption is variable on GI motility/enzymes & blood flow to GI tract
slower onset & peak times
**must pass through the liver via the portal vein “First pass effect”
enteric-coated drugs
Resist disintegration until in the small intestine
coated to resist pharmacoceutic phase
sustained release drugs
Formulation (actual structure of pill w/ different spheres or matrices) which allows drug to slowly release over time
IV route
parenteral route
less convenient, but immediate absorption (faster absorption and peak times)
Risks: no turning back, fluid overload, infection, etc.
IM/SQ route
large spaces b/t cells - drugs absorb by moving b/t cells, through channels and pores
blood flow impacts absorption - Deltoid = high blood flow
less convenient, complications
Bioavailability
The percentage of the administered drug dose that reaches the systemic circulation (bloodstream) unchanged
Oral never 100%, IV is 100%
oral doses require higher dose
Sublingual/buccal route
quick, self-administrable, economic
bitter taste, irritation of mucosa, not large quantities
Protein binding
drugs bind to proteins in body
albumin (plasma protein) - most drugs bind in some way in bloodstream and dependent on level of attraction
can restrict distribution