Pharm Flashcards
pharmacology
study of substances interacting w/ living systems thru chemical processes (binding, activating, inhibiting)
pharmacokinetics. involves: Absorption vs Distribution vs Metabolism vs Excretion/elim
what body does to drug –> determines drug conc in body. drug from administration site to circ vs drug REVERSIBLY goes from circ to tissue vs aka biotransformation; drug modified by enzymes in various cells; active to inactive, active to active/toxic, inactive to active, unexcretable to excretable vs drug/metabolites IRREVERSIBLY elim from body by removing intact drug or removing drug that underwent biotransformation
pharmacodynamics. involves Mechanism of action
what drug does to body. specific biochem interaction where drug produces pharmacological effect
chemotherapy vs pharmaceutics vs pharmacogenomics vs pharmacognosy vs pharmacotherapeutics vs pharmacy vs therapeutics vs toxicology
using drugs to prevent and tx dz vs making drugs vs relationship b/w pt’s genetics and their response to drugs vs study drugs isolated from natural sources like plants and microbes vs using drugs to tx dz vs science involving prep, store, dispense, and use drugs vs using drugs to prevent and tx dz vs study of poisons and organ toxicity
drug resources: small molec drugs vs biologics vs biosimilars
natural (plants, microbes, animals, minerals), semi synthetic (chemically modifying from natural src), synthetic (made in chem lab) vs genetically engineered in living org vs biological product similar to FDA approved product; made from living organisms
excipient
inactive by themselves, goes w/ active ingredient for flavor, bulking/binding, improve manufacture/bioavailability/stability
immediate release vs delayed release vs sustained/extended release vs targeted release vs oral disintegrating tablets (ODT)
conventional, release drug immediately vs release discrete portions some time after admin; enteric coated drugs protect envelope from stomach acid to move to GI tract –> good for acid labile drug vs control drug release for many hours –> slower absorption & longer duration vs release drug at/near intended physiologic site (can be IR or ER) vs disintegrates in saliva, no water needed
is SR/ER drug good for urgent situations?
nope
admin routes: enteral vs parenteral vs other
involves esophagus, stomach, sm/lg intest (PO, SL, PR) vs not involve GI tract (IV, IM, subq, IO) vs inhalation (most rapid), intranasal, intraventricular, topical, transdermal
legend vs nonlegend drugs
rx, more harmful side effects –> don’t self medicate vs OTC, less harmful side effects –> can self medicate
controlled and noncontrolled drugs criteria
based on med use, abuse potential, safety, dependence liability
Schedule I vs II vs III vs IV vs V controlled drugs
highest potential for abuse, no current accepted medical use –> only for research (ex: mj, LSD, heroin) vs high potential for abuse that could lead to physical/physiological dependence (ex: morphine, hydrocodone, amphetamines, cocaine) vs potential for abuse less than I and II that could lead to moderate/low physical dependence or high physiological dependence (ex: codeine, anabolic steroids) vs low potential abuse less than III (ex: alprazolam, diazepam, clonazepam, carisoprodol, tramadol) vs low potential for abuse (ex: combination products w/ limited amts of narcotics, pregablin)
indication vs off label use
med has been evaled for safety and efficacy by FDA –> approved vs rxing meds that has not been FDA approved
adverse drug event vs rxn/side effect
harm to pt from drug exposure d/t drug error; you don’t expect rxn from drug vs pt experiences rxn from drug exposure even if drug admin appropriately; you expect rxn from drug
relative vs absolute contraindication
only rx drug when benefit < risk vs AVOID b/c life threatening
black box warning
most severe warning from FDA about drug
category A vs B vs C vs D vs X
good to go for preg vs no evidence in risk of animal studies w/o controlled studies of preg OR or adverse effects in animal studies w/o controlled human studies vs only give if benefit > risk; evidence of risk on animals (teratogenic, embryocidal) w/o controlled human studies OR no reproduction studies avail for animals or humans vs evidence of fetal risk but benefit > risk vs evidence of fetal risk, risk > benefit –> don’t give
dz oriented evdience vs pt oriented evidence that matters
hard data; answer questions about etiology, pathophysiology, pharmacology; intermediatae or surrogate outcome vs soft data; answers questions that physicians and pts care about and outcome may change practice
how to rx CIII-V vs noncontrolled drugs vs CII drugs
expire 6mo after it’s written, 5 refills up to 6mo period vs no fed specific time limit, VA expires 12mo from date of issue vs no expiration date, no refills, “do NOT fill before [date]”, up to 90d supply
How is drug admin route determined?
Drug properties (water/lipid solubility, ionization) and therapeutic objective (onset, duration, site of action)
Factors influencing drug absorption
pH of area (nonionized = penetrate cell membrane), AUI/BPI; blood flow to absorption site (drug to intestines > stomach b/c intest has more vasculature), total SA for absorption, drug exposure to absorption surface (drug to GI = not good if pt has diarrhea)
1st pass effect/metabolism
Drugs absorbed from gut to liver via hepatic vein before entering circ —> converted to inactive metabolites —> dec bioavailability
bioavailability. How to calculate it?
Rate and extent to which drug reaches circ. How much drug administered, how much drug absorbed (if 100mg of drug = admin, but 70mg of drug = absorbed —> bioavailability = 70%)
When are 2 pharmaceutical equivalents vs bioequivalents?
Have same active ingredient, identical in strength/conc/dose/admin route vs bioavailability of both = not significantly diff
Bioequivalent vs biosimilar based on size and origin
Smaller; chemically synthesized vs bigger; made from living organisms
Factors that affect drug distribution
Blood flow (more vascular = better), capillary permeability (blood brain barrier), binding of drugs to plasma and tissue proteins, size (ex: heparin = too big) and lipophilicity of drug (lipophilic drugs can move thru cell membrane better; hydrophilic drugs can’t —> pass thru slit jxns)
vol of distribution
vol of liquid in which drug needs to be dissolved to mimic same plasma conc; calc by V = D/Co (V = vol of distribution, D = amt of drug in body/total dose, Co = plasma conc at time zero)
one vs two vs multicompartment model of distribution
whole body = 1 compartment –> applicable to drugs that distribute to tissue simul or stay in plasma and elim immediately begins; reality: N/A for majority drugs vs whole body = 2 compartments –> central compartment = init vol of distribution, final compartment = vol of distribution after equil –> applicable to drugs that distribute to tissue slowly or equilibriate slowly b/w plasma and tissue; reality: applicable for majority drugs vs drugs that distribute into mult tissues at significantly diff rates (drugs taken up by vessel rich groups –> muscle –> adipose); so many diverse rates –> drug may never reach equil b/w plasma and tissue
where can metab/biotransformation occur?
liver –> 1st pass effect, has microsomal enzymes; GI tract, lungs, kidney, brain
ex of phase I vs phase II biotransformation rxns
hydrolytic rxns, reductive rxns, oxidative rxns (HRO) vs conjugation rxns, acetylation, glucuronide formation, sulfation, UGTs –> all make it highly soluble
other names and fxns of P-glycoprotein 1 (PGP1) (drug transport protein)
aka multidrug resistance protein 1 (MDR1) or ABC binding cassette sub family B member 1 (ABCB1). Transport drugs back into GI tract, back out of the brain (part of BBB), or into proximal tubule for excretion; uses 2 ATP to pump out 1 molec of drug; lipo>hydrophilic drug preference; protects pt (pumps foreign substances out)
drug transport protein affects?
ADME
renal elim
drug elim thru urine. 1) glomuerular filtration: plasma binding of drug, measure GFR –> 2) active and carrier mediated tubular secretion –> 3) passive tubular reabsorption of nonionized WA/B, ionized WA/B = trapped in nephrons and get elim thru urine, feces, biliary
biliary and fecal elim
drug elim thru liver. 1) active drug and metabolite secretion into bile –> 2) some drugs/metabolites cn be reabsorbed from intestine to body by making them less hydrophilic via gut microbes => enterohepatic recycling
1st vs 0 order/nonlinear kinetics of elim
most drugs use 1st order kinetics; clearance mechanisms = NOT saturable; rate only depends on plasma drug conc; looks like straight line on semilog plot (like MM enzyme plot); rate of admin > rate of elim b/c plasma conc = too low –> as drug = still admin, rate of elim inc and rate of admin = constant –> rate of admin = rate of elim vs for carrier mediated elim; enzymes saturated by unbound drug conc –> plasma drug conc > Km; rate = independent of drug conc
drug Clearance defs and eqn
body’s efficiency in elim drug from circ; vol of plasma from which drug = removed per unit time or rate of drug elim from body relative to plasma drug conc. CL = V/Css (CL = clearance, V = rate of elim, Css = steady state conc)
what is CLtotal vs extraction ratio?
total drug clearance from body from all organs vs fraction of drug cleared by organ
Css. how to reach it?
drug lvls = constant in plasma and target tissue. takes 4-5 half lives to reach Css; when drug = 1st order kinetics, rate of admin > rate of elim b/c plasma conc = too low –> as drug = still admin, rate of elim inc and rate of admin = constant –> rate of admin = rate of elim
what does Css depend on?
drug dose administered, bioavail, drug clearance or half life
2 types of half life: 1/2 life of elim vs 1/2 life of accumulation
time required to reduce drug amt by 1/2 after dosing stops vs time required to inc drug amt by 1/2 during constant infusion
standard dose vs therapeutic range vs drug selectivity
based on trials of healthy volunteers with average ADE –> not suitable for q pt –> individualizes efficacy and toxicity/adverse effects vs Drug conc when pharmacologic response shows desired effects & no adverse effects/toxicity vs ability of drug to show desired effects & minimize adverse effects/toxicity
loading vs maintenance dose
single dose of drug to reach desired plasma conc as fast as possible, followed by MD; base on therapeutic range; usually for IV but if not –> consider bioavailability vs amt of drug given over time to maintain desired plasma conc; based on therapeutic range; rate of drug going in = going out