Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
66 Cards in this Set
- Front
- Back
|
define volume of distribution
|
amount of drug in body/plasma drug concentration
|
|
|
define clearance
|
rate of elimination of drug/plasma drug concentration
|
|
|
relate half life to volume of distribution and clearance
|
t1/2 = (0.7*Vd)/CL
|
|
|
how many half life would it take to reach 87.5% of steady-state concentration?
|
3
|
|
|
the XXXX of plasma protein-bound drugs is affected in liver and kidney disease
|
volume of distribution
|
|
|
loading dose calculation
|
target plasma concentration X volume of distribution / bioavailability
|
|
|
what is the bioavailability in an IV dose
|
100%
|
|
|
maintenance dose calculation
|
target plasma concentration X clearance / bioavailability
|
|
|
does loading dose or maintenance dose change in impaired renal/hepatic function?
|
maintenance dose
|
|
|
define zero-order elimination
|
rate of elimination is constant regardless of drug concentration
|
|
|
how does the plasma drug concentration decrease with time in zero-order elimination?
|
linearly
|
|
|
give 3 examples of zero-order elimination drugs
|
ethanol, phenytoin, aspirin
|
|
|
define first-order elimination
|
rate of elimination is propotional to drug concentration
|
|
|
how does the plasma drug concentration decrease with time in first-order elimination?
|
exponentially
|
|
|
what system is involved in phase I metabolism?
|
cytochrome p-450
|
|
|
what is the overall mechanism of phase II metabolism
|
conjugation
|
|
|
what is yielded after phase I metabolism
|
slightly polar, water soluble metabolites that are often still active
|
|
|
what is yielded ater phase II metabolism?
|
very polar inactive metabolites that are renally excreted
|
|
|
what are 3 mechanisms of phase II metabolism
|
acetylation, sulfation, glucuronidation
|
|
|
what are 3 mechanisms of phase I metabolism
|
reduction, oxidation, hydrolysis
|
|
|
what phase of metabolism do elderly patients lose first?
|
phase I metaoblism
|
|
|
what effect does a competitive antagonist have on a dose-response curve?
|
shift to the right and decrease potency
|
|
|
what effect does a noncompetitive antagonist have on a dose-response curve?
|
shift downward. decrease efficacy
|
|
|
how is the Kd related to the EC50 in a system with spare receptors
|
Kd > EC50
|
|
|
define Kd
|
concentration of drugs required to bind 50% of receptor spots
|
|
|
what is the different between partial agonist and full agonist in a dose-response curve
|
partial agonist has lower maximal efficacy no matter how much dose is increased but both shift to left
|
|
|
how does a partial agonist compare with a full agonist in terms of potency?
|
could be less, more, or equally potent. potency = independent factor
|
|
|
define therapeutic index
|
median toxic dose / median effective dose
|
|
|
what is done in vitro studies?
|
production of compound
|
|
|
what is evaluated in animal testing (3)?
|
efficacy, selectivity, mechanism
|
|
|
what is evaluated in phase I clinical testing? (2)
|
is it safe? pharmocodynamics?
|
|
|
what is evaluated in phase II clinical testing
|
does it work in patients?
|
|
|
what is evaluated in phase III clinical testing?
|
does it work (double=blind)
|
|
|
what is evaluated in the marketing phase of drug development?
|
postmarketing surveillance
|
|
|
how long until patent expires and generics become available?
|
20 years
|
|
|
define drug efficacy
|
maximum effect that can be produced by drug
|
|
|
define drug potency
|
dose required to produce 50% of drug's maximal effect
|
|
|
define LD50
|
lethal dose in 50% of patients
|
|
|
how do you determine steady-state concentration of a drug?
|
dosing rate / clearance
|
|
|
name all of the p450 inducers
|
quinidine, barbituates, phenytoin, rifampin, griseofulvin, carbamazepine
|
|
|
name all of the p450 inhibitors
|
isoniazid, sulfonamides, cimetidine, ketoconazole, erythromycin, grapefruit juice, st. john's wort (inhibitors stop cyber-kids from eating grapefruits)
|
|
|
use for echinacea
|
common cold
|
|
|
ephedra toxicities
|
cns and cardiovascular stimulation, arryhtmias/strokes/seizures at high doses
|
|
|
use for feverfew
|
migraine
|
|
|
feverfew toxicities
|
mouth ulcers, antiplatelet actions
|
|
|
use for ginko
|
intermittent claudication
|
|
|
ginko toxicities
|
anxiety, antiplatelet
|
|
|
kava use
|
chronic anxiety
|
|
|
kava toxicities
|
sedaion, hepatotoxicity, phototoxicity, dermatotoxicity
|
|
|
milk thistle use
|
viral hepatitis
|
|
|
milk thistle toxicity
|
loose stool
|
|
|
saw palmetto use
|
benign prostatic hyperplasia
|
|
|
saw palmetto toxicities
|
decrease libido, hypertension
|
|
|
st. john's wort use
|
mild to moderate depression
|
|
|
st. john's wort toxicities
|
phototoxicity, seratonin syndrome with SSRIs, inhibit p-450 system
|
|
|
DHEA (dehydroepiandrosterone) use
|
improvement in females with AIDS/SLE
|
|
|
DHEA toxicities
|
androgenization in premenopause, estrogen effects in postmenopause, feminization in young men
|
|
|
melatonin use
|
jet lag insomnia
|
|
|
melatonin toxicities
|
sedation, suppress midcycle LH, hypoprolactinemia
|
|
|
what organella is cytochrome p-450 located in
|
smooth endoplasmic reticulum
|
|
|
henderson hasselbach equatoin
|
ph = pka + log (A-/HA)
|
|
|
is a weak acidic charged?
|
no
|
|
|
is a weak base charged?
|
yes
|
|
|
does a charged or uncharged drug pass through membranes easier?
|
uncharged
|
|
|
what effect does alcohol have in pharmacokinetics?
|
it will induces p450 system
|
|
|
how many 1/2 lives does it take to achieve steady state?
|
4-5
|
