What are 4 Principles for clinician when explaining drug effects to pt?
Knowing how a drug works, mechanism of action
The potential adverse effects (ADEs) that are possible
Oral health Education information realted to drug effects
The risk of taking a drug
What is the science of molecular interactions between drugs and body constituents? (Drugs mechanism of action)
Pharmacodynamics
What is the use of pharmacologic agents to diagnose, treat, or prevent disease?
Pharmacotherapeutics
What is the movement of the drug through the body? (absorbtion, distribution, metabolism, and excretion)
Pharmacokinetics
What are some charachteristics of Drug receptors?
cellular macromolecules
location on the cell surface or with in cell
Hundreds of diff. receptors on a single cell
Complementary fit between drug and receptor
Electrochemical charge
Hydrophilic or hydrophobicOnly one drug molecule can occupy a receptor at one time
What is the site of action on cell surface or sith in the cell where the drug molecule acts to initiate an effect?
Receptor site
What are features that determine Receptors functions?
Shape
Location in the body
Relationship to cellular membranes
Binding capacity
What are the 4 types of drug/receptor bonding?
Ionic
hydrogen
Covalent
van der Waals forces
What are the most common types of bonding between drugs/receptors?
Ionic and hydrogen bonding
What attraction require little energy and are made and broken easily.
electrochemical attraction
What bond occur between atoms with opposite charges?
Ionic
What bond occurs when + hydrogen binds to - atoms and is weak?
Hydrogen Bonds
What bond is the strongest type of bond between a drug and its receptor, resulting from the sharing of electrons by two atoms?
Covalent Bond
Tetracycline binding to dentin and discoloring it is an example of what bond?
Covalent
T/F
Affinity is when a drug molecule moves close to its receptor so the attractive forces between them becomes great enough to overcome the random motion if the drug molecule, the drug binds to the receptor. (Force of attraction of a molecule to a receptor site)
True
Drugs with good affinity have greater ________.
Potency
What is the ability for a drug to cause an effect or action?
Intrinsic activity
When a small dose of a drug produces desired effect->good affinity and good intrinsic activity
Strong Agonist
When a drug must be bound to many more recptors to produce the same effect->lower affinity and lower intrinsic activity
Weak Agonist
When a drug has affinity for receptor, but very low intrinsic activity?
Partial Agonist
What is the maximum response produced by a drug?
Efficacy
The dose above which no further benefical drug effect will occur is called what?
Ceiling dose
The lowest dose of a drug that will produce a measurable response is called what?
Threshold dose
What is a drug that interferes with actions of agonist but have no effect in absence of agonist?
Antagonist
Antagonists can be classified into what?
Receptor Antagonist or Non-receptor Antagonist
T/F Receptor antagonist-can be reversible (competitive) or irreversible (non-competitive).
True
Which agonist (either non-competitive/competitive antagonist) has affinity for a receptor but no efficacy, which reduces the potency of the agonist?
Competitive Antagonist
Which Non-receptor antagonist blocks activation pathway or inhibits the agonist directly?
(ex. Local anesthesia blocks sodium channels that promote depolarization of nerve fibers. Causing information about tissue damage not to be transmitted as pain to the brain)
Chemical antagonists
Which Non-receptor antagonist activates pathways that oppose the action of the agonist?
(ex. Epinephrine overcomes effect of histamine on the blood vessel and it becomes constricted)
Physiologic antagonist
Which Non-receptor Agonist are drugs that have both agonistic and antagonistic properties. When used alone-agonist, but when used with another drug-antagonistic.
Mixed-agonists/antagonist
What are the 2 ways Receptors are classified by?
by the type of drug they interact with OR by the response produced by the drug-receptor complex
T/F Certain diseases or drugs taken long term or in large doses, may increase or decrease the number of receptor sites, making a tolerance to a drug so the former dose no longer is as effective.
True
Dose required to produce desired response in 50% of individuals (ED50)
Effective Dose
The dose that produces death in 50% of individuals?
Lethal dose LD50
_____ ____ _______ _____ indicates narrow dose range between minimal and maximal effects.
Steep dose-response curve
Used during drug development to identify safe, effective dose.
ratio of LD50 and ED50 (LD50/ED50)-Higher the numeric value the safer the drug
Therapeutic index
What is the movement of drugs through the body?
Pharmacokinetics
What properties influence movement across a biological membrane?
-Molecular size
-Lipid solubility
-degree of ionization
Small water-soluble substances may pass through channels or pores in cell membrane, but larger molecules can’t fit through, is call what?
Filtration
To help cell reach equilibrium, the drug molecules hang out with high concentration to pass through to low concentration, is called what?
Passive diffusion:
Two types of Specialized transport mechanism is what?
Facilitated diffusion
Active transport
When a drug forms a complex with a component of cell on one side of membrane, then its carried though the membrane and released on the other side. (does not require energy or a concentration gradient.) Called what?
Facilitated Diffusion
the movement of a drug molecule across membranes against concentration gradient and an electrochemical gradient.-Requires Energy because no one is helping it.
Active transport
What the factors influencing the rate of absorption of drugs?
The degree of ionization and pH of tissues
The formulation of a drug (liquid or solid)
The drugs concentration (the greater the concentration=the faster the rate of absorption)
The area of absorptive surface (the greater the area to which the drug is exposed->the faster the rate of
The route of administration
T/F Polar, ionized, water soluble drugs will diffuse across membrane more readily than non-polar, non-ionized, lipid soluble drugs.
False
non-polar, non-ionized, lipid soluble drugs will diffuse across membrane more readily than polar, ionized, water soluble drugs.
Coating that delay the drug to be dissolved and absorbed until it has past the stomach and reached the upper small intestines?
Enteric Coating
What are organs with significant blood flow? (x3)
heart, GI tract, liver
The administration of a drug though the GI tract by either mouth or rectal?
Enteral
The administration of a drug by bypassing the GI tract, usually by injection, but also by inhalation, topical?
Parenteral
What are 3 types of Injections?
Intravenous (IV)
Subcutaneous (SC)
Intramuscular (IM)
*Accurate and immediate deposition of drug into circulation, bypassing absorption phase
*Most predictable ROA, used in emergencies
*Once injected-no recall (less safe than oral)
*Injection site reactions possible
Intravaneous injection (IV)
*Rate of absorption into blood stream is slow and sufficiently constant to produce sustained effect. (ex. Local anesthetic in dentistry, insulin)
*Potential complications: local tissue irritation by sloughing, necrosis, and pain
Subcutaneous Injection (SC)
*Rapid absorption of aqueous solutions into the bloodstream
*Substances too irritating for IV or SC may be given IM
*Deltoid or Gluteal muscles
Intramuscular (IM)
*Sublingual
*Transdermal patch-continued slow release of drug
*Locally applied antimicrobial agent (Arestin)
Topical Application
T/F
Liver, kidneys, heart, and CNS absorb drugs within minutes.
T/F
Excess body fat stores drugs, slows effect
Both statements are true
Plasma Protein Binder _______ reduce the availability of drugs for diffusion into target organs because only the free or unbound drug is capable of crossing membranes.
Albumin
Where does the majority of drug metabolism occur?
Liver
What is the most common and important of drug elimination from the body?
Renal Excretion
_____________ prepares molecule, and the ______ eliminates it via urination
Biotransformation; kidney
___-___ is the time it takes for half the drug to be removed from the body.
Half-life
How many half-lives does it take to approximately remove a drug from the body?
4
______-____ ___________ is a plateau level of drug that accumulates after multiple doses in timed intervals.
Steady-state concentration
____-_____ ________: constant amount eliminated per unit of time
(ex. Alcohol-the enzymes that metabolize the drug are saturated and cannot absorb more drug-resulting in a constant amount of drug being metabolized per unit of time)