Pharmacokinetics and Pharmacodynamics Flashcards
1
Q
pharmacokinetics
- _____: what the body does to the drug
- _____: what the drug does to the body
- clinical pharmacokinetics is the discipline that describes the _____, _____, _____, _____ of drugs
- _____ is the time required for serum concentrate of a drug to decrease by _____ after _____ and _____ are complete
- a drug given orally has to pass through this organ _____ before it reaches its site of action
- _____ is a generic name fo the group of enzymes that are responsible for most drug metabolism oxidation reactions. They are produced in the _____
A
pharmacokinetics pharmacodynamics absorption distribution metabolism excretion half life half liver cytochrome P450
2
Q
physiologic barriers
- _____, _____, _____ barriers
- epithelial lining of GIT: _____
- pH differences between stomach and fundal veins: _____
- blood brain barrier/blood placental barrier: _____
- bi-lipid layer: _____, _____, _____
- transmembrane proteins (_____)
- _____ core and 2 _____ surfaces
A
physical barriers chemical barriers biological barriers phospholipids sterols glygolipids G proteins hydrophobic hydrophilic
3
Q
_____:
- movement of drugs in the body
- four processes
- -_____
- -_____
- -_____
- -_____
drug concentration at sites of action influenced by several factors, such as:
- _____
- _____
- characteristics of _____ (e.g., _____ solubility)
A
pharmacokinetics absorption distribution metabolism excretion route of administration dose drug molecules lipid
4
Q
drug absorption
routes of drug administration
-_____ (po)
-_____: _____, gases, smoke
- mucous membranes
- _____ (sniffing)
- _____
- _____
- injection (_____)
- _____ (IV)
- _____ (IM)
- _____ (SC)
- _____ (IP)
- _____
- _____
-transdermal
A
oral inhalation vapors intranasal sublingual rectal suppositories parenteral intravenous intramuscular subcutaneous intraperitoneal intra-arterial intra-articular
5
Q
drug absorption
-lipid solubility
pKa = pH at which _____ of drug molecules are _____
–uncharged (_____) molecules are _____
–the pKa of a molecule influences its rate of _____ through _____ into the _____
–pH trapping (_____ equation)
-consider a weakly acidic drug (_____)
pH trapping:
- aspirin is _____ in an acidic environment and 1000 times faster diffused through the _____ into the _____ which as a pH of 7.4
- once in the plasma, this acidic drug is _____ and cannot re-enter the _____
- pH varies: stomach 1-2, intestines: 6-7
A
50% ionized unprotonated lipid soluble absorption tissues bloodstream henderson-hasselbalch equation ASA neutral GI mucosa plasma pH trapped GI tract
6
Q
routes of drug administration
- oral drug administration:
- advantages:
- _____, _____, convenient, practical
disadvantages:
- _____ effect
- blood levels are difficult to predict due to multiple factors that limit _____
- some drugs are destroyed by _____
- drugs may get _____ and then _____
- some drugs irritate the _____ system
A
safe economical first pass absorption stomach acids activated broken down GI
7
Q
routes of drug administration
- advantages of infection routes:
- -_____ is more rapid than with oral administration
- -rate of absorption depends on _____ to particular tissue site (_____ > _____ > _____)
- advantages specific to I.V. injection
- -no _____ involved (injects directly into _____)
- rate of _____ can be controlled
- a more accurate prediction of _____ is obtained
A
absorption blood flow IP IM SC absorption blood infusion dose
8
Q
routes of drug administration
disadvantages/risks of injection
-a rapid onset on action can be dangerous if _____ occurs
-recovery from _____ or _____
-if administered too fast, _____ and _____ function could be compromised
-drugs _____ in water or dissolved in _____ liquids can not be given IV
-_____ techniques are necessary
A
overdosing dehydration shock heart respiratory insoluble oily sterile
9
Q
_____:
- the fraction of an administered dose of drug that reaches the blood stream
- -physical properties of the drug (_____, _____, _____)
- -drug formulation (_____, _____, _____)
- -_____ state
- -_____ rate
- -interactions with other _____
- -_____ and _____
- -_____
- -_____, _____, ehtno cultural, socioeconomic
A
bioavailability hydrophobicity pKa solubility sustained release troche pessary fasting gastric emptying drug age gender diet genetic diseae
10
Q
absorption
- it is the passage of drug from the _____ into the _____
- _____: drugs given in solid form must dissolve in the aqueous _____ before they are absorbed. Poorly water soluble drugs (_____)
- _____: passive transport depends on the _____
- area of _____ surface: if the area is larger, absorption is _____
- _____ of absorbing surface: blood circulation removes the drug from the site of absorption and maintains _____ across the _____. _____ blood flow hastens drug absorption
A
site of administration circulation bio-phase Griseofulvin concentration concentration gradient absorbing faster vascularity concentration gradient membrane increase
11
Q
route of administration affects drug administration, because each route has its own peculiarities
- oral application:
- -_____ drugs (_____) are readily absorbed from GIT
- -acid drugs (_____) acid drug absorption from the _____ is faster due to _____ properties
- -basic drugs (_____, _____) are largely ionized in the _____ and are absorbed only from the _____
A
unionized lipid soluble ethanol aspirin stomach non-ionized atropine morphine stomach duodenum
12
Q
presence of food
- _____ the drug and retards _____
- _____ with calcium present in milk
- thyroxine hormone (_____: _____ USP)
- food delays _____. most drugs are absorbed better if taken on an empty stomach
- certain drugs are degraded in the _____ e.g. _____ by acid, _____ by peptidases- ineffective _____
- _____ coated tablets (_____ resistant coating) and sustained released preparations can be used to overcome acid ability, _____ irritancy, and brief duration of action
A
dilutes absorption tetracyclines levothyroxine synthroid gastric emptying GIT penicillin G insulin orally enteric acid gastric
13
Q
presence of other drugs
- drugs can also alter absorption by _____:
- altering motility (_____, _____)
- causing _____ damage (_____)
- alteration of gut flora by _____ may disrupt the _____ circulation
intestinal absorption
-ileum (_____, _____, _____, _____)
A
gut wall atropine metoclopramide mucosal methotrexate antibiotics enterohepatic ADEK
14
Q
subcutaneous and IM
- drug deposited in the vicinity of the _____
- lipid soluble drugs pass readily across the surface of the _____
- absorption from SC site is _____ than that from IM
- application of _____ and muscular exercise accelerate drug absorption by increasing _____
- _____ (preparations with a long action) such as _____ and _____ can be given by these routes
A
capillaries capillary endothelium slower heat blood flow depot preparations benzyl penicillin protamine since insulin
15
Q
topical application
(skin, _____, _____)
systemic absorption depends on _____
only a few drugs significantly _____ intact skin
-_____, _____, and _____
-_____ applied over extensive areas can produce systemic effects and _____ suppression
-mucous membrane of the mouth, _____ and _____ absorb _____ drugs, e.g. _____ cream
A
cornea mucous membranes lipid solubility penetrate nitroglycerine scopolamine estradiol glucocorticosteroids pituitary-adrenal rectum vagina lipophilic estrogen
16
Q
_____:
- it is the passage of a drug from the circulation to the tissue and the site of its action
- the extent of distribution of a drug depends on its _____, _____ at physiological pH, extent of binding to _____ and _____ proteins, and differences in regional _____
- movement of a drug proceeds until an _____ is established between _____ drug in plasma and tissue fluids
A
distribution lipid solubility ionization plasma tissue plasma tissue blood flow equilibrium unbound
17
Q
body fluid compartments -the total body water as a percentage of body mass varies from \_\_\_\_\_ to \_\_\_\_\_, being rather less in \_\_\_\_\_ than \_\_\_\_\_ -body water is distributed into the following main compartments 1. \_\_\_\_\_ 2. \_\_\_\_\_ 3. \_\_\_\_\_ 4 \_\_\_\_\_ 5. \_\_\_\_\_
A
50% 70% women men plasma intestinal fluid intracellular fluid transcellular fluid fat
18
Q
apparent volume of distribution (Vd)
-if drug given IV the body behaves as a _____ compartment with a volume (Vd) Where the drug gets _____ distributed
Vd= _____/_____
A
single homogenous
immediately
dose administered
plasma concentration
19
Q
- drugs extensively bund to plasma proteins are largely restricted to the _____ and have low _____ (_____ is 99% bound to plasma proteins therefore its Vd is 0.1)
- drugs sequestrated in other tissues may have a Vd much more than the total _____ or even _____ (_____)
- drugs may be present in other tissues, and the _____ is low (_____)
- drug poisoning: drugs with large Vd are not easily removed by _____ and need a _____ to chelate them
- chelating agents: _____ for _____
- _____ for _____ (Wilsons disease)
A
vascular compartment Vd Warfarin body water body mass Digoxin plasma concentration bisphosphonates hemodialysis plamsa antidote Ca++ EDTA lead penicillamine copper
20
Q
blood brain barrier
- _____ based and limits the entry of non-lipid soluble drugs (_____)
- _____ carriers like _____ (glycoprotein) present in _____ cells extrude drugs that enter the brain by other processes
- inflammation of the _____ of the brain _____ permeability of the BBB
- drugs: _____ (DA) does not enter the brain, but its precursor _____ does
- used in _____
A
lipid Amoxicillin efflux P-gp brain capillary endothelial meninges increases dopamine levodopa Parkinsonism
