Orientation to Pharmacology Flashcards
What is pharmacokinetics ?
The body’s effect on drugs - involves drug absorption, drug distribution, drug metabolism and drug excretion
What is pharmacodynamics?
This is the impact of drugs on the body
What are the three properties of an ideal drug?
Effectiveness, Safety, and Selectivity
Is there such a thing as an ideal drug?
No- there is no ideal drug that does not cause any side effects.
What is the most important property a drug can have?
Effectiveness - the drug elicits the response for which it is given
What is the therapeutic objective ?
The objective of drug therapy is to provide maximum benefit with minimal harm
Drug _______ , ________, and ____________________ are important determinants of drug responses.
dosage; route; timing of administration
Pharmacokinetic processes determine how much of an administration dose gets to its ______________
sites of action
4 major pharmacokinetic processes-
ADME
Once a drug has reached its site of action, pharmacodynamic processes determine _________ and ________________ of the ___________.
nature; intensity; response
In most cases the initial step leading to a response is the ______________ of a drug to its _____________
binding; receptor. This is followed by a sequence of events that ultimately leads to a response
Characteristics unique to each ______________ can influence the _____________ and ____________________ processes and by doing so can help determine the ________________ to a drug
patient; pharmacokinetic; pharmacodynamic; patients response
Sources of individual variation when it comes to the patients response to a drug
Drug interactions, age, gender, weight, pathologic variables especially the diminished function of the kidneys and liver, the major organs of drug elimination and genetic variables
Genetic factors can alter the _____________ of drugs and can predispose the patient to unique _________ dr
metabolism; drug reactions
No two patients will response identically to the same drug regimen. True or false.
true - everyone is different and genetically unique
To achieve the ___________, we must tailor drug therapy to the _________________.
therapeutic objective; individual
Our ultimate concern when administering a drug is _________________
the intensity of the response
The intensity of the response is determined by the _______________ of a drug at its ______________-
concentration; sites of action
What are factors that determine the intensity of drug responses ?
Administration
Pharmacokinetics
Pharmacodynamics
Sources of Individual Variation
Important events will take place after the ________________ is delivered and these must be __________ to.
Medication; responded
Remember the MLB pitcher analogy that likened the nurses response to medication administration and response to a pitcher throwing a pitch and anticipating what would happen next
What is the role of the FDA in drug regulation and safety?
The FDA regulates the pharmaceutical industry by approving drugs for marketing and use. Its aim is to make drugs safer, more effective and more affordable. It advances public health and aids public in getting accurate science based information.
It also provides rigorous oversight of drug safety after a drug has been approved.
The FDA regulates: Foods Dietary Supplements Drugs Prescription and Non-prescription Biologics Vaccines Blood and Blood products Medical Devices Tongue depressors Bed pans Heart Pace makers Electronic: Products that give off radiation Xray equipment Cosmetics Veterinary Products Tobacco Products
What is the most reliable way to objectively assess drug therapies ?
Randomized Controlled Trials
What are OTC agents ?
What is CAM ?
Over the Counter agents such as vitamins and supplements
they are the most common form of Complementary and Alternative Medicine
Commonly used dietary supplements include
Cranberry Juice Echinacea Garlic Ginger Root Ginkgo Biloba Green Tea Probiotics St. John’s Wort Valerian Root
FDA regulations for dietary supplements
dietary supplements do not have to be approved by the FDA
Manufacturer must notify the FDA of efficacy claims
Has authority to intervene if supplement becomes harmful
Only after it has been released for marketing
What does pharmacokinetics determine ?
How much of an administered drug gets to its sites of action
Drug absorption factors
Rate of Dissolution- before a drug can be absorbed, it must first be dissolved; drugs with rapid dissolution have a faster onset than drugs with a slow dissolution
Surface Area: major determinant of rate of absorption; the larger the surface area, the faster the absorption
Blood Flow:drugs are absorbed most rapidly from sites where blood flow is high
Lipid Solubility: highly soluble drugs are absorbed more rapidly than drugs whose lipid solubility is low; lipid-soluble drugs can readily cross membranes, whereas low lipid-soluble drugs cannot
pH Partitioning
What are the different absorption patterns for IV, IM, SQ and Oral routes ?
IV is instantaneous absorption
IM and SQ are both relatively more rapid in being absorbed
Oral absorption is slowest
What is the distribution of the drug determined by?
Blood flow to tissues
Ability to exit the vascular system
Ability to enter the cell
What is an abscess ?
A puss filled pocket with no internal blood flow- antibiotics would not reach the bacteria there and would not prove effective unless the abscess is drained
Tumors have _________________ ______________ supply, which would affect drug therapy.
limited blood
Factors affecting the passage of the drug through the cell membrane
Lipid solubility
presence of a transport system
What is metabolism defined as for drugs ?
Where does most drug metabolism take place ?
The enzymatic alteration of a drug structure
Most drug metabolism takes place in the liver
To directly penetrate membranes ….. a drug must be
lipid soluble
What organ accounts for the majority of drug excretion ?
The kidneys
Glomerular Filtration
Passive Tubule Reabsorption
Active Tubular Secretion
Drugs are removed from the body through urine (renal excretion) and sweat, bile, saliva, breast milk and expired air (all non renal excretion methods)
Decreased kidney function = delayed excretion
Compare effect of healthy kidneys on drug’s duration of action with that of failing kidneys
Healthy kidneys will limit the duration of action of many drugs while failing kidneys result in an increase in the duration and intensity of drug responses
Drugs must cross cell membranes by what 3 ways ?
- Through Channels or Pores
- Aid of a Transport System
- Direct Penetration of a Membrane
Very few _________ cross membranes via ________________ because of how small they are; only the smallest of compounds pass through these channels; some of these compounds include: ________________
drugs; channels/pores; SODIUM and POTASSIUM
What do transport systems of cells do ?
Move drugs from one side of the cell membrane to the other
Will transport systems carry any drug ?
No they are selective; it is dependent on the drugs structure
What is one of the most important transporters of the cell?
P Glycoprotein
What is P Glycoprotein ?
a multi-drug transporter protein; It carries many drugs out of cells and can be found in many cells in the LIVER, KIDNEY, PLACENTA, INTESTINES, CAPILLARIES OF THE BRAIN
Discuss the action of P Glycoprotein within different organs in the body
In the liver P-glycoprotein transports drugs into bile for excretion
In the kidneys P-glycoprotein pumps drugs into the urine for excretion
In the placenta P-glycoprotein transports drugs back into maternal blood to reduce fetal drug exposure
In the intestines P-glycoprotein transports blood into the intestinal lumen reducing drug absorption into the blood
In the brain capillaries, P-glycoprotein pumps drugs into the blood thereby limiting access to the brain
