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Exam One
Exam One
115
Pharmacology
Undergraduate 3
09/25/2011

Additional Pharmacology Flashcards

 


 

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Term
Drug
Definition
any chemical that can affect living processes
Term
Pharmacology
Definition
study of drugs and their interactions with living systems
Term
Clinical Pharmacology
Definition
study of drugs in humans
Term
Therapeutics
Definition
the use of drugs to diagnose, prevent, or treat disease or to prevent pregnancy
Term
3 Most Important Properties of an “Ideal Drug”
Definition
effectiveness, safety, selectivity
Term
Six Rights
Definition
right drug, dose, time, route, patient, documentation
Term
Route
Definition
a drug’s route of administration affects the rate and extent of absorption of the drug (enteral, parenteral, and topical)
Term
Pharmacokinetics
Definition
determining how much of an administered dose gets to its sites of action; consisting of absorption, distribution, metabolism, and excretion; it can be thought of as the impact of the body on drugs
Term
Pharmacodynamics
Definition
the impact of drugs on the body
- binding of drug to its receptor, sequence of events → response
-patient's functional state (tolerance, etc. – individual variation)
-placebo effects
Term
Individual Variation
Definition
age, gender, weight, pathologic variables such as diminished functioning of kidneys and liver, and genetic variables that can alter the metabolism of drugs and predispose a patient to unique interactions
Term
Seven Aspects of Drug Administration
Definition
preadministration assessment, dosage and administration, evaluating and promoting therapeutic effects, minimizing adverse effects, minimizing adverse interactions, making PRN decisions, managing toxicity
Term
Preadministration Assessment
Definition
- collecting baseline data to evaluate therapeutic/adverse responses
- identifying high-risk patients such as those with liver and kidney impairment, genetic factors, drug allergies, pregnancy, elderly and pediatrics
Term
Dosage and Administration
Definition
drugs with different indications, dependent on dosage, different routes, IV extravasation
Term
Evaluating and Promoting Therapeutic Effects
Definition
-evaluating therapeutic responses and knowing rationale for drug (why they are taking it, how long it takes to work)
- promoting patient adherence
- implementing nondrug measures (music, massage, etc)
Term
Minimizing Adverse Interactions
Definition
thorough drug history – even OTC drugs, food, and herbals
Term
Making PRN Decisions
Definition
know the reason for drug use and be able to assess the patient’s medication needs
Term
Managing Toxicity
Definition
early identification and signs, know procedure for toxicity management
Term
Landmark Drug Legislation
Definition
- start of regulation = 1906 Federal Pure Food and Drug Act - required that drugs be free of adulterants (nothing about safety or effectiveness)
- 2003 = PREA (pediatric research equity Act) FDA allows limited clinical trials on children
- 2007 = (FDA Amendments Act) FDA also includes limited drug trials on pregnant women
Term
Randomized Control Trial (RCT)
Definition
use of control, randomization, and blinding
Term
Stages of New Development
Definition
- preclinical testing (animals), clinical testing
- phase I - healthy volunteers (look at kidney and liver)
- phases II and III - mild to severe form of disease volunteers
- phase IV - postmarketing surveillance
Term
Pharmacokinetics
Definition
the study of drug movement throughout the body including drug metabolism and excretion
Term
Site of Most Common Excretion
Definition
kidney
Term
Site of Most Common Metabolism
Definition
liver - detect size of liver through palpitation; hepatomegaly indicates poor liver function
Term
3 Ways to Cross the Cell Membrane
Definition
channels and pores, transport systems, direct penetration of membrane
Term
Channels and Pores
Definition
very few drugs can pass through this, only the smallest compounds can pass and it has to be the correct channel (small ions such as Na and K)
Term
Transport Systems
Definition
- carriers that move drugs from one side of the cell membrane to the other (some require energy, some don’t); all systems are selective
-p-glycoprotein - transports drugs out of cells! Unique system to bind and be brought out after they have affected their therapeutic response (kidneys, liver, placenta, intestine and capillaries of brain)
Term
Direct Penetration of Membrane
Definition
most common; the drug must be lipo-philic (lipid soluble)
Term
Absorption
Definition
the rate at which a drug leaves it site of administration, and the extent to which absorption occurs
Term
Bioavailability
Definition
first-pass effect reduces bioavailability of the drug < 100%. If first-pass is very high there is low bioavailability
Term
Affecting Factors
Definition
route, foods or fluids administered with drug, absorptive surface, rate of blood flow, acidity of stomach, GI motility
Term
Ionization of Drugs
Definition
- acidic drugs - will ionize in basic media and accumulate on the alkaline side of a pH gradient
- basic drugs - will ionize in acidic media and accumulate on the acidic side of a pH gradient
Term
Ion Trapping
Definition
Ex = aspirin. Aspirin ingested and disintegrated in stomach. Since Aspirin is acidic, it will be nonionized in stomach and therefore lipid soluble and able to cross the membrane into the bloodstream. Once into the plasma (which is slightly alkaline) the Aspirin becomes ionized and can’t move back into the stomach.
Term
First-pass Effect
Definition
metabolism of a drug and its passage from the liver into the circulation, only have this with enteral drugs - doesn’t happen when given IV
Term
Distribution
Definition
transport of a drug in the body by the bloodstream to its site of action
- blood flow to tissues, exiting the vascular system, protein binding, entering cells
Term
Blood Flow to Tissues
Definition
rate at which drugs are delivered to a particular tissue depends on blood flow to that tissue (abscesses and tumors can affect blood flow and perfusion)
Term
Exiting the Vascular System
Definition
- in typical capillary beds, drugs pass between capillary cells rather than through them
- BBB - tight junctions between the cells that compose the walls of most capillaries in the CNS so only drugs that are lipid soluble or have a transport system can cross the BBB to a significant degree
Term
Protein Binding
Definition
- drugs can form reversible bonds with various proteins. Plasma albumin is the most abundant and important. Drugs that are protein bound are not free to exact action (only free drugs can have therapeutic effects)
- once a drug is protein bound, it remains bound until either receptor on protein down regulates and releases the molecule or is inactivated, or some other drug with a higher affinity for that protein molecule knocks it off (competitive)
Term
Entering Cells
Definition
some drugs must enter cells to reach site of action, most drugs must enter cells to undergo metabolism and excretion, but many drugs produce their effects by binding with receptors on the external surface of the cell membrane
Term
Metabolism
Definition
- the biologic transformation of a drug into an inactive metabolite, a more soluble compound, or a more potent metabolite (also known as biotransformation)
- transforms drug into nonactive form to be excreted
- pro-drugs - need to be broken down and metabolized before affecting its response
- only free drug (not protein bound) can affect a response
- delayed drug metabolism results in accumulation of drugs and prolonged action of the drugs
- stimulating drug metabolism causes diminished pharmacologic effects
- the most important consequence of drug metabolism is accelerated renal excretion (changing the drug from lipo to hydrophilic)
Term
Factors That Decrease Metabolism
Definition
CV dysfunction, renal insufficiency, starvation, obstructive jaundice, slow aceytlator, erythromycin or ketaconazole
Term
CV dysfunction
Definition
no blood flow to the liver, have decreases/changes in metabolism
Term
Renal Insufficiency
Definition
need kidneys to excrete drug after it’s metabolized
Term
Starvation
Definition
more acidic environment in stomach, decreases protein in blood therefore starving the liver of nutrients and micronutrients which upsets metabolism
Term
Obstructive Jaundice
Definition
unable to metabolize drugs and substances normally
Term
Slow Acetylator
Definition
genetic component metabolizing slower than normal leading to toxicity
Term
Erythromycin or Ketaconazole
Definition
inhibits the P450 enzymatic system
Term
P450
Definition
- hepatic microsomal enzyme system. P450 refers to cytochrom P450, a key component of the system. P450 = CYP. 3 CYP families metabolize drugs – CYP1, CYP2, and CYP3 which all metabolize drugs are also composed of multiple forms, each of which metabolizes only certain drugs
- metabolism doesn’t always result in a smaller molecule
- mono-oxygenase - tranform lipophilic drugs into hydrophilic so they can be excreted
Term
Excretion
Definition
the elimination of drugs from the body (main organ – kidney)

SEE NEPHRON
Term
Nephron
Definition
blood moves through afferent arteriole, filtered through the glomerulus, and the remaining blood goes into the efferent arteriole. The filtrate however moves on through the proximal tubule. If the drug molecules are not biotransformed (metabolized) into a hydrophilic substance, it will be reabsorbed from the PT back into the bloodstream and won’t be excreted
Term
Drug Onset
Definition
the time it takes for the drug to elicit a therapeutic response
Term
Peak
Definition
the time it takes for a drug to reach its maximum therapeutic response
Term
Duration
Definition
the time a drug concentration is sufficient to elicit a therapeutic response
Term
Pharmacodynamics
Definition
study of the biochemical and physiologic effects of drugs and the molecular mechanisms by which those effects are produced – basically the study of what drugs do to the body and how they do it
Term
Maximal Efficacy
Definition
- indicated by highest dose-response curve
- higher efficacy = smaller dose with best response
- lower efficacy = large dose with mediocre response
Term
Potency
Definition
relates to how many mg needed to get a certain dose response
Term
receptor
Definition
any functional macromolecule in a cell to which a drug binds to produce its effects
Term
Non-competitive Antagonists
Definition
bind irreversibly to receptors and reduce the maximal response that an agonist can elicit because of fewer available receptors

Ex = narcan knocking off an opiod to reverse toxicity by blocking opiods from binding with opiod receptors
Term
Competitive Antagonists
Definition
compete with agonists for receptor binding; bind reversibly to receptors, the receptor will be occupied by whichever agent has the higher affinity for that receptor – if there is equal affinity the molecule present in the highest concentration will bind
Term
Regulation of Receptor Sensitivity
Definition
- number of receptors on the cell surface and sensitivity to agonists can change in response to continuous activation or continuous inhibition
- receptors on cell surface are either recycled or down regulated
- when the receptors of a cell are continually exposed to an agonist, the cell usually becomes less responsive – desensitized, refractory, or down regulated
- continuous exposure to antagonists cause the cell to become hypersensitive (supersensitive) from the synthesis of more receptors
Term
Drug Responses that DO NOT Involve Receptors
Definition
simple physical or chemical interactions with other small molecules including: antacids, antiseptics, saline laxative, chelating agents (which are drugs that bind to other drugs such as activated charcoal to reduce toxicity) and eye drops (saline eye drops only!)
Term
3 Possible Drug-Drug Interactions
Definition
- one drug may intensify the effects of the other (potentiative) - Ex = morphine and diazepam are both CNS depressants, if given together they will both increase the others CNS depression
- one drug may reduce the effects of the other (inhibitory) - Ex = HCTZ and spironolactone are opposite diuretics, one is potassium wasting one is potassium sparing
- the combination may produce a new response not seen with either drug alone
Term
Pharmacokinetic Drug-Drug Interactions
Definition
altered absorption, altered distribution, altered renal excretion, altered metabolism, interactions that involve P-Glycoprotein
Term
Altered Absorption
Definition
antacids elevating gastric pH, laxatives, drugs that depress peristalsis, drug induced vomiting, adsorbent drugs
Term
Altered Distribution
Definition
competitive drugs, alteration of extracellular pH
Term
Interactions That Involve P-Glycoprotein
Definition
transport drugs out of cells which results in reduced absorption, reduced fetal drug exposure, reduced brain exposure, increased drug elimination
Term
Drug-Food Interactions
Definition
- can result in increased or decreased absorption
- grapefruit juice effect
Term
Decreased Absorption
Definition
food can affect rate and extent of absorption

Ex = milk and tetracycline/digoxin and fiber can result in therapeutic failure
Term
Increased Absorption
Definition
high calorie meals and saquinavir (if not taken with a meal it will reduce the absorption)
Term
Grapefruit Juice Effect
Definition
inhibits the metabolism of certain drugs and raises the drug’s blood levels
Term
Drug-Herb Interactions
Definition
St. John's Wart is the big one
Term
Adverse Drug Reactions
Definition
any noxious, unintended, and undesired effect that occurs at normal drug doses – excludes excessive dosages
Term
Side Effect
Definition
a nearly unavoidable secondary drug effect produced at therapeutic doses; it may develop soon after a drug is initiated or not until the drug has been taken for weeks or months
Term
Toxicity
Definition
adverse drugs reaction caused by excessive dosing (but may even occur with normal dosing depending on the patient’s genetics or for example neutropenia which leads to risk for infection when being treated with anti-cancer medication)
Term
Allergic Reaction
Definition
an immune response with prior sensitization. When re-exposure occurs, the drug can trigger an allergic response; the intensity of allergic reactions is largely independent of dosage
Term
Idiosyncratic Effect
Definition
an uncommon drug response resulting from a genetic predisposition
Term
Iatrogenic Disease
Definition
disease produced by drugs – the drug may not cause an actually disease but will produce the signs and symptoms that come along with that disease (once off the drug the signs and symptoms will cease)
Term
Organ Specific Toxicity
Definition
- hepatotoxicity - some damage to the liver or cellular structure of the liver (a lot of these!)
- nephrotoxicity - damage to the kidneys
- ototoxicity - damage to the inner cilliary or inner ear resulting in hearing loss
Term
QT Interval
Definition
the amount of time it takes for your ventricles to repolarize in between each contraction; when the QT interval is prolonged, patients can develop a dysrhytmia known as torsades de pointes, which can progress to potentially fatal ventricular fibrillation
Term
Individual Variation in Drug Responses
Definition
body weight and composition, age, kidney disease, live disease, acid-base imbalance, altered electrolyte status
Term
Body Weight and Composition
Definition
BSA versus weight
Term
Age
Definition
- infants --> organ immaturity
- elderly --> organ degeneration
Term
Kidney Disease
Definition
reduced excretion and increased toxicity
Term
Live Disease
Definition
reduced metabolism and increased toxicity
Term
Acid-Base Imbalances
Definition
pH changes that alter absorption, distribution, metabolism, and excretion of drugs
Term
Altered Electrolyte Status
Definition
rare for electrolyte changes to have significant impact on drug responses
Term
Tolerance
Definition
- decreased responsiveness to a drug as a result of repeated drug administration
- pharmacodynamic tolerance, metabolic tolerance, tachyphylaxis, placebo effect
Term
Pharmacodynamic Tolerance
Definition
MEC of a drug is abnormally high
Term
Metabolic Tolerance
Definition
accelerated drug metabolism
Term
Tachyphylaxis
Definition
reduction in drug responsiveness brought on by repeated dosing over a short time (not common)
Term
Placebo Effect
Definition
drug response caused by psychologic factors and not by biochemical or physiologic properties of a drug
Term
Bioavailability
Definition
- ability of the drug to reach the systemic circulation from its site of administration (PO preps, not parenteral) such as tablet disintegration time, enteric coatings, sustained release formulations
- variable absorption may also be caused by changes in gastric pH, diarrhea, constipation, or food in the stomach
Term
Pharmacogenetics
Definition
study of genotypes people have that impact absorption, metabolism, distribution, and excretion of drugs – ability to give targeted drugs and dosages without ADRs
Term
Acetyl Enzymes
Definition
- fast - so rapid that the drug may be excreted before affecting therapeutic responses
- slow - increased risk of causing toxicity
Term
Pregnancy
Definition
- first-trimester is the period of greatest danger for drug-induced developmental defects; during the third trimester, drugs are eliminated much quicker because blood flow through the kidneys is doubled
- essentially all drugs can cross the placenta – some cross more readily than others
Term
Teratogen
Definition
Drug that causes birth-defects
Term
FDA Pregnancy Risk Categories
Definition
A, B, C, D, X
Term
Category A
Definition
relatively safe drug to give to a pregnant mom
Term
Category B
Definition
slightly more risk, animal studies show no fetal risk
Term
Category C
Definition
greater risk, animal studies show fetal risk of harm but no human studies done, but risk to mom may be higher than risk to fetus where giving the drug is acceptable
Term
Category D
Definition
proven risk to fetus – weigh benefits to mom vs. risk to fetus
Term
Category X
Definition
never give this drug to a pregnant woman (exception in diagnosed with cancer while pregnant – in this situation a decision needs to be made)
Term
Breast-Feeding
Definition
breast-fed infants are at risk for exposure to drugs consumed by the mother
Term
Pediatric Absorption Considerations
Definition
gastric pH less acidic than in adults, gastric emptying is slowed, first-pass elimination by liver is reduced because of immature liver function (however may still have first-pass effect but may affect bioavailability), topical absorption faster through the skin, IM absorption faster and irregular because muscles are smaller than in adults but irregular because each child (even at same age) has different sizes of muscles and blood flow to that area
Term
Pediatric Distribution Considerations
Definition
TBW greater than in adults, Greater TBW = Lower fat content, decreased level of protein binding so more free drug available, immature BBB
Term
Pediatric Metabolism Considerations
Definition
immature liver that doesn’t produce enough microsomal enzymes which can result in toxicity, older children may have increase metabolism requiring higher doses
Term
Pediatric Excretion Considerations
Definition
kidney immaturity affects GFR and tubular secretion (if kidneys can’t secrete a drug they won’t be able to excrete it → accumulation) and decreased perfusion rate of the kidneys
Term
Methods of Dosage Calculation
Definition
mg/kg… to calculate BSA you need height in cm, weight in kg.
Term
Geriatric
Definition
- 65 y.o. and older
- these patients have altered pharmacokinetics with more sensitivity to drugs and wider variation of reactions from multiple pathologies, polypharmacy, and organ degeneration
- change in adipose tissue, TBW, and lean muscle mass lead to risk of addiction
Term
Physiologic Changes in the Geriatric Patient
Definition
CV, GI, hepatic, renal
Term
CV Changes
Definition
- decreased CO = decreased absorption and decreased distribution
- decreased blood flow = decreased absorption and decreased distribution
Term
GI Changes
Definition
- increased pH = decreased or increased absorption depending on acidity of drug
- decreased peristalsis = delayed gastric emptying
Term
Hepatic Changes
Definition
- decreased enzyme production = decreased metabolism
- decreased blood flow = decreased metabolism
Term
Renal Changes
Definition
- decreased blood flow = decreased excretion
- decreased renal function = decreased excretion
- decreased GFR = decreased excretion
Term
Geriatric Distribution Considerations
Definition
increased percent of body fat, storage of lipid soluble drugs, decreased TBW distribution in smaller volumes so concentration is increased and effects are more intense, increased level of free drug from reduced protein binding
Term
Geriatric Metabolism Considerations
Definition
liver produces less microsomal enzymes, affecting drug metabolism and reduced blood flow to the liver
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