QUIZLET Unit 1 - Intro to Pharmacology (mixed) Flashcards
Body of knowledge concerned with the action of chemicals on biologic systems, especially by binding to regulatory molecules (receptors) and activating or inhibiting normal body processes
Pharmacology
It’s how the drug reacts to the receptor
Pharmacodynamics
- what the body does to the drug
- Includes absorption, distribution, metabolism, and elimination
Pharmacokinetics
time it takes to reduce drug to half its concentration
half-life
it refers to an idea that masking and social
distancing temporarily held off infections, which are now occurring as population behavior allows the greater spread of pathogens.
Immunity debt
area of pharmacology concerned with the use of chemicals in the prevention, diagnosis, and treatment of disease, especially in humans
Medical Pharmacology
Area of pharmacology concerned with the undesirable effects of chemicals on biologic systems
Toxicology
amount of medication required to effect the
cure of a disease.
therapeutic dose
the amount of a drug or other agent that if
administered to an animal or human will prove fatal.
lethal dose
Finds the exact mechanism of action of drugs; identifies the receptors
Pharmacogenomics
Area of pharmacology concerned with the undesirable effects of chemicals on biologic systems
Toxicology
amount of medication required to effect the cure of a disease.
Therapeutic dose
the amount of a drug or other agent that if administered to an animal or human will prove fatal.
Lethal dose
It finds the exact mechanism of action of drugs; and identifies the receptors
Pharmacogenomics
Any substance that brings about a change in biologic function through chemical actions
Drug
Specific molecule in the biologic system that plays a regulatory role
Receptor
Solid drug form examples
Aspirin, atropine, & lozenges
Liquid drug form example
nicotine, ethanol, vaccines, anesthetics (halothane, isoflurane, desflurane, and sevoflurane), chlorhexidine, paracetamol, nasal spray, carbocysteine, albendazole
Gas drug form example
nitrous oxide, nitric oxide, xenon, oxygen
Drug size for transversion to different barriers of the body
1000 MW
Drug size for selective binding
100 MW
Chemical forces or bonds through which the drug interacts with the receptors
DRUG RECEPTOR BONDS
Drug size that is given directly at the site of action
> 1000 MW
Strongest and irreversible bond
Covalent bond
More common and weaker bond
Electrostatic bond
Actions of the drug on the body
Pharmacodynamics
bond that is the weakest and highly lipid soluble drugs
Hydrophobic bond
Actions of the body on the drug
Pharmacokinetics
occurs when drug X binds to Ra and there is an effective capacity
Agonist
Occurs when drug Y binds to Ri and there is no effect
Inverse agonist
Activates receptor-effector system to the maximum extent (Ra-D pool; activated form)
Full agonist
Binds to the same receptors and activate them in the same way but do not evoke as great a response
partial agonist
Binds to a site on the receptor molecule separate from the agonist binding site
Allosteric modulators
-Drug has a stronger affinity for the Ri-D pool (nonfunctional form)
-Reduces constitutive activity
-Results in effects that are opposite of the effects produced by conventional agonists
Inverse agonist
-Binds to a receptor, compete with and prevent binding by other molecules
Antagonist
o Inactive precursor
o Must be administered and converted to the active drug by biologic process inside the body
o Takes a longer time to take effect in the body compared to regular active drugs
Prodrug
Movement of molecules through the watery extracellular and intracellular spaces
Aqueous diffusion
Movement of molecules through membranes and other lipid structures
Lipid diffusion
Drug transported across barriers by mechanisms that carry similar endogenous substances
Transport by special carriers
Predicts the movement of molecules across a barrier
Fick’s Law of Diffusion
the amount absorbed into the systemic circulation; amount of drug administered
Bioavailability
Route of administration with:
o Maximum convenience
o Absorption may be slower and less complete
o Some drugs have low bioavailability when given oral
o Subject to first-pass effect
Oral
Route of administration with:
o Instantaneous and complete absorption
o Bioavailability is 100%
o Potentially more dangerous, high blood levels reached if administration is too rapid
Intravenous (IV)/ Parenteral
Route of administration with:
o Absorption is often faster and more complete (higher bioavailability) than oral
o Large volumes (>5 mL into each buttock) if the drug is not irritating
o First-pass effect is avoided
o Heparin cannot be given by this route because it causes bleeding in the muscle
Intramuscular (IM)
Route of administration with:
o Slower absorption than IM route
o First-pass effect is avoided
o Heparin can be given by this route because it does not cause hematoma
Subcutaneous
Route of administration with:
o Permits absorption direct into the systemic circulation, bypassing hepatic portal circuit and first-pass metabolism
o Slow or fast depending on formulation of the product
Buccal and Sublingual
Route of administration with:
o Partial avoidance of first-pass effect
o Not completely absorbed as compared to the sublingual route
o tend to migrate upward in the rectum where absorption is partially absorbed into the portal circulation
o Larger amounts of unpleasant drugs are better administered rectally o May cause significant irritation
Rectal (Suppository)
Route of administration with:
o For respiratory diseases
o Delivery closest to the target tissue
o Results into rapid absorption because of the rapid and thin alveolar surface area
o Drugs that are gases at room temperature (e.g., NO2), or easily volatilized (anesthetics)
Inhalation
Route of administration with:
o Application to the skin or mucous membrane of the eye, nose, throat, airway, or vagina for local effect
o Rate of absorption varies with the area of application and drug’s formulation
o Absorption is slower compared to other routes
Topical
Route of administration with:
o Application to the skin for systemic effect
o Rate of absorption occurs very slowly
o First-pass effect is avoided
Transdermal
Rate of elimination is constant regardless of concentration
Zero order elimination
Rate of elimination is proportionate to the concentration
First order elimination
Neutral molecule that can form a cation (+ charged) by combining with a proton (hydrogen ion)
Weak Base
Ionized, more polar, more water soluble when they are protonated
Weak base
Neutral molecule that can reversibly dissociate into an anion (- charged) and a proton (hydrogen ion)
Weak acid
Not ionized, less polar, less water soluble when they are protonated
Weak Acid
- determines the concentration gradient between blood and the organ
- E.g. skeletal muscle and brain
A. Size of the organ
B. Blood flow
C. Solubility
D. Binding
Size of the organ
Important determinant of the rate of uptake
A. Size of the organ
B. Blood flow
C. Solubility
D. Binding
Blood flow
Binding of drugs to macromolecules in the blood or tissue compartment will tend to ________ the drug’s concentration in that compartment.
A. Increase
B. Decrease
C. No effect
increase
Well-perfused organs (4)
brain, heart, kidneys, and splanchnic organs
T/F: If the drug is very soluble in cells, the concentration in the perivascular space will be lower and diffusion from the vessel into the extravascular tissue will be facilitated
True
- Refers to the amount of drug in the body to the concentration in the plasma
- Vd
Apparent volume of distribution
Inactive as administered and must be metabolized in the body to become active
○ Eg, levodopa, minoxidil
Prodrugs
T/F: Action of many drugs is terminated before they are excreted
True
T/F: Prodrugs are active as administered and have active metabolites as well
False
Determinants of the duration of action for most drugs (2)
Dosage, Rate of elimination following the last dose
T/F: Drug elimination is the same as drug excretion
False
________________ , elimination of the parent molecule by metabolism is not synonymous with termination of action
A. For most drugs
B. For most drugs, excretion is by way of the kidneys (except anesthetic gasses-lungs)
C. For drugs that are not metabolized
D. None of the above
For most drugs, excretion is by way of the kidneys (except anesthetic gasses-lungs)
_____________________ , excretion is by way of the kidneys (except anesthetic gasses-lungs)
A. For most drugs
B. For most drugs, excretion is by way of the kidneys (except anesthetic gasses-lungs)
C. For drugs that are not metabolized
D. None of the above
For most drugs
______________ , excretion is the mode of elimination
A. For most drugs
B. For most drugs, excretion is by way of the kidneys (except anesthetic gasses-lungs)
C. For drugs that are not metabolized
D. None of the above
For drugs that are not metabolized
T/F: A small number of drugs combine irreversibly with their receptors, disappearance from the bloodstream is not equivalent to cessation of drug action
True
T/F: Rate of elimination is proportionate to the concentration
True
T/F: Drug’s concentration in plasma increases exponentially with time
False
T/F: Half-life of elimination is constant regardless of amount of drug in the body
True
T/F: Concentration of such drug in the blood will decrease by 50% for every half-life
True
Most drugs are eliminated through?
First order elimination
T/F: Rate of elimination is constant regardless of concentration
True
Occurs with drugs that saturate their elimination of mechanism at concentrations of clinical interest
Zero order elimination
Concentration of such drugs in plasma increase in linear fashion over time
False
T/F: With higher doses, there will be bigger chances of toxic effect because the patient may not be able to eliminate it
True
