Exam II Basic Pharm Principles

Question 1

pharmacotherapeutics

Answer 1

the use of specific drugs in the prevention, treatment, or diagnosis of disease

Question 2

pharmacodynamics

Answer 2

what the drug does to the body

the quantitative effects of a drug on the body

Question 3

pharmacokinetics

Answer 3

what the body does to the drug
quantitative, time dependent changes of both plasma drug concentration and the total amount of drug in the body, following the drug’s administration by various routes
-ADME

Question 4

absorption

Answer 4

drug and its intake/absorption at site of administration

• lipid or water soluble
• ionized
• speed of action desired
• systemic or local action
• enteral vs. parenteral
• some drugs can change based on the pH inside the body
• bioavailability is based on drug absorption:
  - plasma concentration/dose

Question 5

distribution

Answer 5

• occurs mainly via circulation
• wide variance in organs and tissues ability to take up a drug
• non-vascular tissues and plasma proteins can take up or bind drugs
• rate at which tissues take up a drug depends on vascularity of region that absorbs it

Question 6

sites of metabolism

Answer 6

liver* (primary)
kidneys
lungs
skin
GI tract

Question 7

biotransformation (aka drug metabolism)

Answer 7

capable of altering drugs in 4 ways:
1-conversion of active drug to inactive drug
2-conversion of active drug to active or toxic metabolite (prolongs activity of drug)
3-conversion of inactive prodrug to active drug (prodrug activated in the liver - cytoxin)
4-conversion of unexcretable drug to excretable metabolite (non-water soluble to water soluble)

Question 8

Metabolic Pathways

Answer 8

phase I reaction: usually precedes Phase II but not always
-chem mod. through oxidation, reduction, or hydrolysis,
-cytochrome P450 system is most common oxidative pathway (CYP3A4 (usually in liver)
phase II reaction: intend to make things nonwater soluble into water soluble
-conjugate drug to form large polar molecule
-enhance solubility and excretion in urine or bile

Question 9

elimination

Answer 9

renal* primary
renal excretion relies on water solubility
drugs also excreted in small amounts via bile, feces, sweat, lungs
-elimination halflife: amount of time over which the drug concentration in the plasma decreases to one-half of its original value
-ranges from days (diazepam- 80 hr half life bc metabolites have similar activity, digoxin) to minutes (NE)
longer halflives can be more troublesome bc they stay around longer

Question 10

enteral

Answer 10

administration type: uses GI tract to enter body, not many risks upon entry

• includes ORAL, SUBLINGUAL/BUCCAL, RECTAL
• advantages of oral type that it’s simple, safe, convenient, inexpensive, no pain, no infection, no rapid spikes in plasma levels (the # rises and tapers off slowly), larger vascular network available in oral and rectal mucosa.
• disadvantages this is extremely variable administration of a drug bc transporters and receptors are proteins and so vary by person, this is the most variable and complex pathway of admin, slow delivery, requires GI absorption and function, First Pass Effect means sometimes the liver can and will metabolize the drug before it gets moved into the systemic circulation so it may end up having a much lower availability, GI environment is harsh, GI irritation can occur.

Question 11

parenteral

Answer 11

administration type: does NOT use GI tract for entry into body

• includes IV, INTRAMUSCULAR, SUBCUTANEOUS, also meds can be implanted (ie insulin pump)
• advantages: rapid delivery, high bioavailability, avoid first-pass metabolism, avoid GI environment, good control of delivered dose
• disadvantages: irreversible, infection risk @ injection sites, pain and fear, need for skilled delivery, limited drug delivery with SC and IM

Question 12

other routes of administration

Answer 12

• inhalation (large surface area rapid delivery, complicated for self-delivery not easy to do correctly)
• intranasal
• intrathecal (some chemo drugs baclofen within a sheath, directly into subarachnoid space)
• topical
• phonophoresis (sound waves to drive meds into skin)
• ionophoresis (electricity to drive into skin)

Question 13

intrathecal

Answer 13

**some chemo drugs ex: baclofen
med is inserted within a sheath in the body, directly into subarachnoid space specifically of spinal column
-in neural membranes

Question 14

transdermal

Answer 14

application of medicine across dermis skin

Question 15

first pass effect

Answer 15

First Pass Effect means sometimes the liver can and will metabolize the drug before it gets moved into the systemic circulation so it may end up having a much lower availability

Question 16

volume of distribution

Answer 16

dose/[drug]plasma
-volume of distribution=vd is low for drugs contained in plasma, high for drugs distributed in muscle or adipose… low # means drug is contained in plasma and primarily water soluble:
-aspirin: 11L (low)
-digoxin: 500L (high)
uniform distribution is AT or NEAR 42L
-most drugs circulate with plasma proteins (ex: albumin, and others, which makes this not available to do other things in the body since it’s occupied by acting as a transfer ptn), drugs can be taken up into tissues and tissue compartments oher than**

Question 17

conjugation

Answer 17

ways to change drugs once they;re inside the body. during metabolic pathway, during Phase II, drug can be conjugated to form a large polar molecule

Question 18

therapeutic dosing

Answer 18

amplification effects can occur if dosing is too high, therapeutic window exists for all drugs, smaller doses mean theyll last shorter amount of time, look@therapeutic dosing graph

Question 19

enzymatic induction

Answer 19

liver enzymes inducted:
tobacco smoke increases drug activiy
-phenlytoin and carbemazeprine (anti-seizure)
-rifampin (antibiotic)
-ethanol (alcohol)
-benzopyrene

Question 20

enzymatic inhibition

Answer 20

liver enzymes inhibited:

• prilosec (omeprazole)
• erthryromycin- antibiotic
• cimetidine
• amiodarone (heart rhtyhm)
• grapefruit juice (slow down rate of activity of meds, gets on enzymes in the sm intestine)

Question 21

half-life

Answer 21

period of time required for the concentration or amount of drug in the body to be reduced by one-half. We usually consider the half life of a drug in relation to the amount of the drug in plasma

Question 22

G protein coupled receptor

Answer 22

“guanine-protein coupled receptor”
-constitute a large protein family of receptors that sense molecules outside the cell and activate inside signal transduction
most common receptor in humans, 70% of interactions use these receptors

Question 23

second messenger

Answer 23

molecules that relay signals received at receptors on the cell surface — such as the arrival of protein hormones, growth factors, etc. — to target molecules in the cytosol and/or nucleus

Question 24

desensitization

Answer 24

decreased affinity
inactivation, changes to receptor activity that’s in place (enzymatic activity and phosphorilation) - can happen quickly. modification of substances already in the cells
ligand doesn’t bind as frequently or readily to the receptor

Question 25

supersensitivity

Answer 25

increased affinity
changes to receptor activity that’s in place (enzymatic activity and phosphorilation) - can happen quickly. modification of substances already in the cells
ligand binds more freuqnelty and readily to receptor

Question 26

up/down regulation

Answer 26

changes in # of receptors
An increase of a cellular component is called upregulation. An example of downregulation is the cellular decrease in the number of receptors to a molecule, such as a hormone or neurotransmitter, which reduces the cell’s sensitivity to the molecule

Question 27

refractory

Answer 27

Resistant to treatment, as of a disease

Question 28

agonist

Answer 28

a molecule that binds a receptor and causes a response

Question 29

antagonist

Answer 29

“blockers” - inhibits the action of the agonist but has no effect… inhibition

Question 30

chemical antagonist

Answer 30

non-receptor antagonist

Question 31

physiologic antagonist

Answer 31

non-receptor antagonist

opposite effect of another drug, for ex: thryoid issues and the beta blocker role

Question 32

competitive antagonist

Answer 32

ligand binds where another could bind, compeing with agonist for same site.

Question 33

noncompetitive antagonist

Answer 33

for ex: a channel doesn’t open, even when agonist is bound.

Question 34

partial agonist

Answer 34

activates receptor but produces only a partial response, even when all sites are bound. affinity for receptor (often high), response observed isn’t observed; opioid pain relievers…morphine is considered a strong agonist, though)

Question 35

graded dose-response curve

Answer 35

response of one individual to a drug, small dosage means no response observed, then after threshold dose there’s an increase in response, at ceiling effect, no more receptors to interact with- saturated.

Question 36

efficacy

Answer 36

capacity for a drug producing a desired result or effect

Question 37

potency

Answer 37

lower dose of drug has higher impact

Question 38

quantal dose-response curve

Answer 38

you measure based on what occurs during drug administration, on or off response,
for ex: yes or no, or 50% is the effective dose.
Therapeutic / toxic / lethal effect

Question 39

therapeutic window

Answer 39

range of doses that fall within range (cumulative % exhibiting therapeutic effect), beneath the toxic effect

Question 40

therapeutic index

Answer 40

TI=TD50/ED50… bigger implies a safer med (further toxic dose is away from effective dose). tylenol has a high index, chemo drugs have a TI close to 1 since they’re inherently toxic.

TD=toxic dose/ ED=Effective Dose

Question 41

absorption

Answer 41

nonpolar substance will diffuse through more readily than a polar substance. pH of GI tract changes drastically from stomach to sm intestine and this can affect where and how drugs are absorbed.