pharmacology quiz 2 Flashcards
pharmacokinetics
the motion/movement of drugs in your body
pharmacokinetics process
absorption
distribution
metabolism
excretion
absorption
the movement of a drug from its site of administration into the blood
the rate of absorption determines ____
how soon the effects will take place
the amount of drug determines ____
how intense the effects will be
factors affecting absorption process (6)
-rate of dissolution
-surface area
-blood flow
-lipid solubility
-pH partitioning
-route of administration
routes of administration (2)
enteral (GI tract)
parenteral (outside GI tract)
enteral (GI tract)
oral (by mouth/PO)
parenteral (outside GI tract)
Intravenous (IV)
subcutaneous (subQ)
intramuscular (IM)
oral, by mouth, PO barriers to absorption
epithelial lining of GI tract
oral absorption patterns
slow and variable
advantages of PO meds (3)
-safer than injections
-ideal for self administration
-easy,convenient, cheap
disadvantages of PO meds (4)
-GI irritation
-requires cooperative pt
-inactivation
-variability
intravenous (IV) barriers to absorption
none
IV absorption pattern
instantaneous and complete
advantages of IV (4)
-rapid onset
-control
-permits use of large fluid volumes
-permits use of irritant drugs
disadvantages of IV (4)
-high cost, difficulty, inconvenience
-irreversibility
-infection
-high risk
intramuscular (IM) and subcutaneous (subQ) barriers to absorption
none
IM and SubQ absorption pattern
VARIABLE
-water solubility
-blood flow
advantages of IM and SubQ (2)
-can be used for poorly soluble drugs
-can be used for depot preparations
disadvantages of IM and subQ (4)
-discomfort
-inconvenience
-can cause muscle and nerve injury with improper technique
-bleeding risk
when parenteral administration is preferred: (6)
-emergencies
-situations requiring tight control
-GI incompatibility
-treatment with drugs that cannot cross membranes
-condition better treated with long-acting preparation
-pts who cannot or will not take oral preparation
distribution
the movement of drugs throughout the body
distribution process
-blood flow to tissues
-drug’s ability to enter cells
-drug’s ability to exit the vascular system
drug metabolism
the enzymatic alteration of drug structure to a more water-soluble form that can be excreted
special factors/considerations in drug metabolism
-age
-first-pass effect
-nutritional status
-competition between drugs
excretion
the removal of drugs from the body
excretion routes
-bile
-urine/feces
-sweat/saliva
-breast milk
-expired air
monitoring of drug responses
plasma drug levels
correlation between response to drug and level in plasma
monitoring of drug responses
two important levels
-minimum effective concentration (MEC)
-toxic concentration
monitoring of drug responses
therapeutic range
determines whether the drug can be safely given
monitoring of drug responses
drug half-life
determines dosing interval
monitoring of drug responses
repeated dosing
determines rate and extent of accumulation
peak
highest level of drug in the body, 1-2 hours after given
trough
lowest level of drug in body, right before next dose
maintenance
lower dose to maintain state of drug in body
loading
higher dose to get response
ED50
average effective dose
LD50
lethal dose
pharmacodynamics
the force or power of a drug
drug drug interactions outcomes (3)
potentiate
inhibit
new response
potentiate
intensifies the effects
inhibit
reduce the effects
new response
effect not seen with single drug alone
drug v food (5)
-absorption
-drug metabolism
-drug toxicity
-drug action
-timing
