Week 1: Chapter 2,3,4,5,6,8,9,10 Overview ~ Ray Flashcards
Please add and edit as you see fit :) Week 1 objectives: Differentiate between pharmacodynamics and pharmacokinetics. Recall/employ main concepts of rational drug selection and cost when prescribing. Summarize special drug treatment considerations in pediatric and geriatric patients. Recall mechanisms that cause drug interactions. Recall various herbal therapies and their uses.
What are the stages of drug development? Could you describe each phase?
Preclinical: The drug is targeted, and ingredients are isolated. Medical chemists can create compounds and slightly adjust them to evaluate the perfect combination of properties. Studies are performed on cells, isolated tissues, and organs. Toxicology and safety testing determine the potential risk a compound poses to people and the environment.
Clinical phase I: establishes biological effects (safe dosages and pharmacokinetics) on healthy people at different doses.
Clinical Phase 2: drugs are used to treat diseases in a small number of sick patients. Outcomes are evaluated. <100 people.
Clinical Phase 3: The drug is compared with current medications in the market to evaluate outcomes—larger population group (~1000).
Explain the Dose-Response Curves
The higher the concentration of a drug at its site of action, the more the drug will bind to its receptor and the greater the response will be. With a greater number of drug molecules in the vicinity, more are likely to interact with the receptor and produce a response. Note: far fewer receptors may be needed to produce maximal effect.
IE a graph to show the concentration or dose of a drug in relation to that drugs percent of maximum response.
Explain Graded Response
Biological effects that can be measured continually up to the maximal capacity of the biological system (For example, the use of BP to monitor the effectiveness of Anti-HTNs)
Explain Quantal Response
Quantal Responses: Effects are present or absent. Examples are seizures, pregnancy, or death. NOTE:s can be both. For example, antiseizure medications can be graded by the decrease in seizures, whereas Some medicines can be quantal when there is an absence.
What is potency?
Potency is how much drug is needed to produce a biological response. Describes the difference in concentration of dosage of different drugs required to make the same effect. Higher potency requires less dose/concentration.
What is efficacy? Provide examples.
The maximal effect a drug can produce.
Example: Mild pain relief meds, such as Tylenol, cannot relieve the same pain as Oxy regardless of the dose.
What is intrinsic activity?
the ability of a drug to produce a response ONCE IT HAS OCCUPIED specific receptors.
Some drugs can occupy receptors and provide little to no response. The lower the intrinsic activity the lower efficacy the drug has.
What is Therapeutic Index (TI)? What is the formula?
It is the ratio of the lethal dose to the therapeutic dose. The higher the TI, the safer it is considered.
TI= LD50/ED50
What is Structure-Activity Relationship (SAR)
The correlation of chemical structure with pharmacological activity. Chemical interactions determine a drug’s activity at a particular receptor type, and changes in chemical structure result in changes in pharmacological activity.
What is a receptor?
Receptors are large molecules, usually proteins, that interact with and mediate the action of drugs.
Receptors provide a theoretical framework for understanding and predicting drug actions and the relationship between dose (or concentration) and effect. Also, receptors within the same “superfamily” often share properties.
What are Ion Channel Receptors?
Ion Channel receptors transmit signals across the cell membrane by increasing the flow of ions and altering the electrical potential or separation of charged ions across the membrane. Responses are rapid onset and short duration.
For example, when Acetylcholine (ACh) binds on TWO (2) nicotinic ion receptor sites, the channel opens, and Sodium and Potassium cross the cell membrane to initiate a response.
If you have pro can someone as a pic please
What types of Ion Channel Receptors are there?
ACh (nicotinic)
Gamma-aminobutyric acid (GABA)
Excitatory amino acids (glycine, aspartate, glutamate, etc.).
What are G-protein coulpled receptors? Explain the structure.
G-protein–coupled receptors are proteins that cross the cell membrane seven (7) times, creating a pocket in which drugs can interact. There is a “tail” intracellularly.
What happens when G-proteins are activated?
When a drug is attached to the binding site, the G protein undergoes a conformational change like a “twist”. The G-protein is then released. The, now-activated, G-protein can interact with effector proteins. These effector proteins then make second messengers.
How many subunits are in G-proteins? What are their names?
Alpha, Beta, Gamma.
What is Phosphorylation?
Placing a phosphate group on a protein is a way of marking it for activation or inactivation.
What is a Transmembrane Receptor?
Transmembrane receptors consist of extracellular hormone-binding domain and an intracellular enzyme domains that phosphorylates the amino acid tyrosine
How do transmembrane receptors get activated? What happens?
The hormone binds to the extracellular binding site, the receptor conformation changes, and two receptors bind to each other, activating the enzyme and sustaining the effect. Different receptors catalyze the phosphorylation of tyrosine residues on various downstream signaling proteins.
What are intracellular receptors? what happens when they are activated?
Intracellular receptor resides in the cytoplasm until it binds with a drug that has glucocorticoid activity. Binding of the drug displaces a stabilizing protein and permits the folding of the receptor into its active conformation. The receptor then moves to the nucleus, where it controls the transcription of genes by binding to specific DNA sequences
What are enzymes?
biological molecules that encourage specific chemical reactions in the body.
I think of enzymes as action tasks. Enzymes are the lock, and drug is the key.
What is full agonist
drugs that produce receptor stimulation and conformation change every time they are bonded. they do not need all the available receptors to produce maximum effect.
what are antagonists
Drugs that occupy a receptor without stimulating them and prevent other molecules from occupying the same site to produce a response.
what are the two types of antagonists (explain both)
Competitive: compete for the same binding site. Drugs can overcome antagonistic effects with higher concentrations of competing agonists.
Non-competitive: antagonist irreversibly bind somewhere else in the enzyme, changing it and making it unusable. Increasing drug does not increase effectiveness.
what are partial agonists?
Bind to receptors but when they occupy the receptor sites, they stimulate only some of the receptors. They trigger a lower maximal response than a full agonist. This is sometimes called intrinsic activity
What is pharmacokinetics
The absorption, distribution through the body, metabolism, and excretion of drugs
What is absorption?
The way in which medications are presented to the body
What is bioavailability? Which route has the highest bioavailability?
The percentage of the admin dose that enters the bloodstream (regardless of route).
IV admin has the highest bioavailability as it goes straight into circulation and skips first pass.
What is peak blood levels?
The highest concentration of drug in the body. Rapid absorption leads to higher peak blood levels, with a risk of greater toxicity and side effects. IV push leads to the highest peak blood levels.
What is distribution?
the process of drugs moving throughout the body.
What are properties that affect distribution?
Molecule size, charge, pH (ionization), chemical structure, transport systems.
When does passive diffusion occur most readily?
When drugs are small and uncharged and have the right balance between water and lipid solubility, preferring lipophilic molecules.
What is the Henderson-Hasselbalch equation
pH=pKa + log([A-]/[HA])
A- (ionized) HA = non-ionized
how is pH defined
-log[H+]
what is pKa?
The acid dissociation constant (pKa) is the pH at which a drug is half charged and half uncharged. it is a FIXED property
What is passive diffusion?
Passive diffusion is a process through which drugs cross some type of biological barrier, such as a cell membrane or a layer of cells, based on the concentration difference between the two sides of the barrier. passive diffusion proceeds until the concentration of un-ionized drug is the same on both sides. As a result, pH differences can cause more drugs to accumulate based on the fraction of un-ionized and ionized molecules. This is called ion trapping.
what are plasma proteins?
Proteins are made in the liver, and drugs can bind to them. Albumin is the most common.
Others: alpha-1-acid glycoprotein, cortisol-binding globulin, sex hormone–binding globulin, and lipoprotein
What happens when drugs are bonded to plasma proteins? (aka why is it importaint)
They can freely circulate the blood system. (plasma proteins are the Ubers). They also protect the drug from metabolism/excretion. However, it prevents the interaction of drug molecules with their site of action. Can make a blood level of a drug appear high when it is actually not active.
what are transporters?
Membrane proteins that facilitate the movement of molecules across the cell membranes. They are directional (influx/efflux).
examples:
MRCP1, P-glycoprotein
What does a non-competitive or irreversible antagonist do to the dose response curve?
Lowers the max efficacy of the drug, it will not be able to reach same ED100
what are metabolites
drugs that are chemically altered by enzymes
what is metabolism?
Process of changing one chemical into another, usually using or creating energy.
what is first-pass metabolism?
metabolism by the liver following oral administration
Who is the MPV of metabolism?
The P450 enzyme family 😎
What is phase I of metabolism
nonsynthetic reactions.
Oxidation, reduction, and hydrolysis reactions.
They unmask polar groups, which improves water solubility and prepares drug molecules for further metabolic reactions.
They are either eliminated or go to phase II
What is phase II of metabolism?
Synthetic or conjugation reactions.
Metabolites are linked/conjugated to highly polar molecules, making them water-soluble.
What is drug selectivity?
Ratio for the drug amount or concentration producing undesired effects to the concentration producing the desired effect. How many times would a therapeutic dose have to be given to undesired effects.
Example. If a drug produces desired effect at one tablet and no undesired effects, but you will see undesired effects at 5 tablets, the selectivity ratio is 5.
What are the differences between Brand and Generic drugs?
Have same active ingredient but differ the inactive ingredients, fillers, capsules or coloring. There is usually variations in the rate of absorption due to differences in the time it takes to break down and dissolve.
What is a single nucleotide polymorphism (SNPs)
Minor mutations in proteins that can result in metabolic activity changes.
Can charged/ ionized molecules can passively diffuse through a cell membrane?
No, uncharged or unionized molecules are more lipid soluable and more readily pass through the cell membrane.
What are the most important CYP subfamilies?
CYP3A4, CYP2D6
what is competition?
when two drugs are metabolized by the same enzyme. Often the enzyme can metabolize both drugs, but sometimes one drug will be preferentially metabolized, delaying the metabolism and extending the half-life of the competing drug.
What is first order metabolism?
Metabolism is related to drug concentration so that a fixed FRACTION of a drug is metabolized per hour.
characterized by half-life. (elimination per hr is dependent on drug concentration). Exponential.
1st half-life: 50%
two half-life: 75%
third half-life: 87.5%
Can G-couple protein receptors have a rebound effect?
Yes, receptors can be desensitized or number downregulated with stimulation. This can limit the amount of time a drug can be given and can cause a rebound effect when abruptly stopped.
What is zero-order metabolism?
Metabolize a constant amount of drug each hour regardless of dose in body. Linear.
What are prodrugs?
Drugs that rely on metabolism to become active.
what is enzyme induction?
When some drugs increase the expression of drug-metabolizing enzymes
What is Excretion?
the process in which drugs are transferred from inside the body to outside the body.
what is the primary organ for excretion?
the kidney
Briefly explain how the kidney excretes drugs
Urine production starts in the glomerulus, where ultrafiltration occurs (substances in plasma pass through pores in the glomerular capillary membrane). As the filtrate moves through the lumens of the nephrons, some re-enter circulation via passive diffusion, creating a concentration gradient. pH plays a large part (ion trapping)
What impacts renal excretion rates?
GFR; size, charge, and degree of protein binding.
How does biliary excretion work?
Drugs enter the liver through the first pass, and then some enter the bile, where it is dumped into the intestines.
the biliary system uses three active transport.
What is enterohepatic cycling
When drugs are excreted in bile, sent to the intestines, and then reabsorbed.
How does competition at a plasma protein effect drug activity.
If one drug is competing in the blood for the same plasma protein as another or one drug kicks another off of the plasma protein due to it having higher affinity, it will change the typical bound to unbound ration allowing more free fraction drug to have effect.
Example Warfarin is typically 98% bound and 2% free, if a drug even knocks off 2% of the bound, it will make 4% unbound and double the typical circulating volume.
What is volume of distribution?
The theoretical volume that a drug would have to be dissolved in to explain the level of drug in the blood. This number can give an idea of where the drug might be distributed.
If we administer 100mg of a drug and the blood concentration is 2 mg/l then the Vd would be 50L.
Where is Total Body Water Distributed?
about 60% (~40L) of body weight is water ~2/3 the total body water is intracellular, ~1/3 extracellular. 5% of body water is plasma (4-5L)
What is rational drug selection?
“patients receive medications appropriate to their clinical needs, in doses that meet their own individual requirements, for an adequate period of time, and at the lowest cost to them and their community”
What is the 6 step process for rational drug prescribing?
- Define the problem
- specify the therapeutic objective
- choose the treatment
- start the treatment
- educate the patient
- monitor effectiveness.
what is the “I Can PresCribE A Drug” MNEUMONIC?
Indication
Contraindications
Cost/compliance
Efficacy
Adverse effects
Dose/Duration/Direction
What are the Pharmacodynamic factor considerations in drug selection?
Therapeutic index
What are pharmacokinetic factor considerations with drug selection?
Think ADME:
Admin, Distribution, Metabolism. Excretion
(see details of each one in other flashcards)
What are the therapeutic factor considerations with drug selection?
What are patient considerations for drug selection?
Previous adverse drug reactions, health beliefs, current drug therapy, age, pregnancy,
What are the considerations for drug selection (overview)?
Pharmacodynamics, pharmacokinetics, therapeutic factors, safety, cost, patient factors, provider factors
What are some major federal drug laws? (not sure if we will be tested on)
Food, drug, and Cosmetic Act of 1906 (proper labeling)
What are legend drugs?
drugs that under federal law require prescription
What is the difference between label and off label use?
Label use: FDA approved (has summary regarding pharmacodynamic/pharmacokinetic)
Off-label use: non-FDA approved but able to prescribe (less legal protection)
What are schedule I drugs?
Drugs with no medical or legal use (such as LDA, heroine, mescaline)
What are schedule II drugs?
Drugs that can be prescribed (no refills) and can only be phoned in in emergencies (written prescription within 7 days).
Example: Narcotics, stimulants (cocaine, amphetamine, methylphenidate)
Depressants (pentobarbital, secobarbital)
What are schedule III drugs?
prescriptions must be rewritten after six months or after 5 refills
phone/fax allowed.
examples: Narcotics (mixed with nonnarcotics), stimulants (benzphetamine, chlorpheniramine)
Depressants (butabarbital)
steroids, testosterone
what are schedule IV drugs
same as class III but less penalties for illegal possession.
Example: benzos, pentazocine
What are schedule V drugs?
It is the same as nonprescription drugs and may be dispensed without a prescription.
Examples: pregabalin and cannabidiol drugs.
what is an Averse Drug Reaction (ADR)?
any undesirable or unintended effect after administration of a medical product, whether or not the effect is considered related to the medical product (
What are the two clarifications of ADRs
Pharmacological (Intrinsic): predictable based on drug’s MOA and is typically dose related (85-90%)
Idiosyncratic: unpredictable and often serious (10-15%)
What is the hapten hypothesis?
Drugs that hapten (low molecular weight chemicals what become antigenic when covalently minded to a carrier molecule) that elicit an immune-mediated reaction
Explain Type I Immune-Mediated reaction
IgE-mediated.
Immediate hypersensitivity (local or systemic; mild to servere)
Explain Type II Immune-Mediated reaction
Antibody-dependent cytotoxicity (antibodies attach to antigens and induce cell/tissue destruction through complement system)
Explain Type III Immune-Mediated reaction
Immune complex hypersensitivity (occur when aggregates of antigens and IgG and IgM antibodies create insoluble immune complexes in vessels or the blood that may be deposited in tissues )
Explain Type IV immune-mediated reaction
cell-mediated or delayed hypersensitivity
What are rapid reactions ADRs
occurs during or immediately after the administration of a medication
what are first-dose reactions
occur after the first dose of a medication and generally does not occur with repeated doses
what are early reaction (ADR)
occurs early in treatment and generally resolve with continued therapy as the patient develops tolerance.
what are intermediate reactions (ADR)
Occur after repeated exposure to a medication.
what are late reactions
Occur after prolonged exposure to an offending agent.
What are delayed reactions?
Occur at variable points in time after drug exposure and can even occur after the discontinuation of a drug.
hoes does the FDA define serious ADRs
those that result in death, are life-threatening, result in hospitalization (new or prolonged), are disabling or incapacitating, produce congenital abnormality or birth defect, or require an intervention to prevent one of these outcome
What are common causes of ADRs
1/3 from medication errors
1/3 from allergic reactions
Top drugs: insulins, opioid-containing meds, anticoags, amoxicillin meds, antihistamines.
How does genetics play a role in ADRs
variations in enzymes
How does age play a role in ADRs
In children: meds must be tailored to their weight and BMI. They also have immature organ function
In older adults: decrease metabolism and clearance.
what is genetic polymorphism
multiple differences of a DNA sequence found in at least 1% of the population
what is genetics?
study of heredity and its variations
what is genomics
study of the complete set of genetics information in a cell, organism, or speicies
what is pharmacogenetics?
Study of the influence of heredity factors on the response of individual organisms to drugs
what is pharmacogenomics (PGx)?
The study of genetic differences among people and the impact these differences have on the uptake, effectiveness, toxicity, and metabolism of drugs.
what is SNP?
single-nucleotide polymorphism
what is a wildtype?
the most common copy of the gene (think of it as the base model)
what is the nomenclature used for PGx?
Thus, for instance, CYP2D6 written in italics refers to the standard copy of the gene, whereas CYP2D6*1 (pronounced “star 1”) is the variant.
when is a gene caleld polymorphic
allelic variations occur throughout a given population at a stable rate of less than 1%
what are the four phenotypes associated with genetic polymorphysm?
Poor metabolizers (PMs) lack working enzymes.
Intermediate metabolizers (IM) are heterogeneous (one wild-type and one variant)
Extensive metabolizers (EMs) have two standard functioning alleles.
Ultrarapid metabolizers (UMs) have more than one functioning copy of a specific enzyme).
what are the most common CYPs
CYP2D6, CYP2C9, and CYP2C19 (40% of metabolism)
what are p-glycoproteins (PgP)?
Membrane-bound, ATP-dependent transport system responsible for the EFFLUX of a variety of xenobiotics from cells to the extracellular fluid
what is phytomedicine?
the practice of using plants or plant parts to achieve a therapeutic cure”
What is herbal medicine?
when the plant or a constituent of the plant is identified as the primary reason for its effect or specific treatment of a disease or symptom
what is CAM?
Complementary and alternative medicine.
what is pharmacognosy?
Pharmacology that uses the chemicals from plants, molds, fungi, insects, and marine animals for their medicinal value
How are Western herbal medicine classes?
According to their therapeutic properties and constituents of the plant.
what is Dao?
The concept that humans are a microcosm of a larger macrocosm.
What is the principle goal of Traditional Chinese Medicine (TCM)?
To determine an imbalance (diagnosis before the presence of disease) or the source of a disease that has resulted from an imbalance, and to prevent the progression of the imbalance, support self-healing, and treat the disease.
TMC considers the person consuming the herb!
What is qi
free flow of energy. High qi results in healing and a balance.
How are TCM herbs classified?
classified by their energies, quality, season, tastes, directions, and actions on the body
What does Ayurvedic medicine mean?
Study of life.
developed in ancient India.
What is the goal of ayurvedic medicine?
similar to TCM.
Encompasses a myriad of therapies based on the constitution of individuals and nature of their particular disease.
How is Ayurvedic herbology classifies
mild (food)
moderate (spices)
strong (herb).
three doshas
vita (air/ether)
pitta (fire/water)
Kapha (water/earth)
Cinammon
Tx of diabetes, GI complaints, and inflammatory issues.
ginger
prevention of neausea/vomiting
what is pharmacoeconomics
analysis of the costs and consequences of any given health-care–related treatment or service.
what facors incleunce pharmacoeconomics?
Research type
Clinical outcomes
Efficacy
Safety
Adverse drug reaction
Drug-drug reaction
Hospital admission, clinic visits
Humanistic outcomes
Patient satisfaction with care
Quality of life measured by validated instrument
Economic outcomes
Cost associated with immunosuppressive therapy
Cost to treat adverse drug reactions
Cost to treat drug–drug interactions
Cost to treat long-term toxicity (nephrotoxicity, hypertension)
Cost of laboratory work-ups
what is direct cost?
Costs that can be directly attributed to the treatment or disease state in question. (med prices, provider time, Dx tests, transportation, child care.
what is indirect cost?
These costs derive from morbidity and mortality and include things such as loss or reduction of wages owing to illness or the costs associated with premature death.
Can be measured using human capital cost and willingness to pay.
what is intangible costs
Difficult to measure cost (grief).
what is cost-of-illness analysis
Cost of illness identifies the costs of a specific disease in a given population (medical and nonmedical resources, loss of productivity)
what is cost-minimization analysis?
looks at two or more treatment alternatives that are considered equal in efficacy and compares the cost of each alternative in dollars.
what is cost-effectivness.
compared Different clinical outcome
Justify the incremental cost increase for the therapeutic benefit from extra costs associated with treatment.
what is cost-benefit analysis?
Cost of a specific treatment or intervention are calculated and then compared with the dollar value of the benefit received.
Whether a given benefit will exceed the cost needed to implement it
what is cost-utility analysis
Costs of the treatment choice are in dollars and the outcomes are expressed in terms of patient preference or quality-adjusted life years (QALY)
What is genetic bioequivalence
When drugs are exactly the same (brand vs generic). FDA requirement for generics.
Contain the same active ingredients as the innovator drug. Active ingredients make the drug effective against the disease or condition it is treating.
Come in the same dosage form. If the brand name is a capsule, the generic should also be a capsule.
Be administered in the same way. If the brand name is taken orally, the generic should also be taken orally.
Be identical in strength.
Have the same conditions of use.
Be bioequivalent (an equal rate and extent of drug absorbed in the bloodstream).
Meet the same standards for identity, strength, purity, and quality.
Be manufactured under the same standards that the FDA requires for the manufacture of innovator products
what is free fraction
amount of drugs not bound to proteins during distribution.
what are pediatric considerations for adoption?
gastric fluids are neutral in the first hrs of life.
gastric output same as adults at 2yo.
slightly slower gastric-emptying
what are pediatric considerations for distribution?
albumin is 80% of an adult and alpha-1 acid glycoprotein is less as an adult.
bilirubin competes with albumin
What are pediatric considerations for metabolism?
Same?
what are pediatric considerations for elimination?
GFR and secretion/reabsorption impaired.
give LESS dose
What are maternal considerations for absorption?
30-50% increase gastric/intestinal emptying
decrease gastric secretions and increasing mucus production (aka decrease pH)
What are maternal considerations for distribution?
increase cardiac output and renal blood flow.
volume expansion by 50%
decrease Cmax
