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Pharmacology - Block 1 - Part 2

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davidwurbel7's version from 2016-08-14 05:04

Pharmacokinetics 6 - Excretion

Question Answer
This is not affected by lipid solubility of the drugGlomerular Filtration
The size (MW<65000) of the drug, protein binding and renal blood flow affect thisGlomerular Filtration
Giving Ammonium chloride or Vitamin C or Cranberry juice will do this to urineAcidify
Giving Sodium bicarbonate or Acetazolamide will do this to urineAlkalinize
Probenecid will compete with this drug in transport systemsPenicillin
Probenecid, competes with Uric acid for its reabsorption in renal tubule. Therefore probenecid is useful in the treatment of this conditionGout
The metabolism to convert a drug to an excretable form plus excretion of a drugElimination
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Pharmacokinetics 7 - Advanced Pharmacokinetics

Question Answer
The body may be considered as a single compartment in which the drug is uniformly distributedSingle Compartment Model
The body has a central compartment and a peripheral compartment. The drug can distribute from the central compartment to the peripheral compartment and back againTwo Compartment Model
Most parameters of a drug can be calculated from this which is determined by administering a dose of drug and then measuring the drug plasma concentration at different times Plasma Concentration vs Time Curve
Maximal drug concentration obtained with a doseC max
Time at which C max is reachedT max
Time plasma concentration remains greater than minimum effective concentration (MEC)Duration of Action
The plasma concentration of a drug required to produce a therapeutic effectMinimum Effective Concentration
The range between toxic level and the minimum effective concentrationTherapeutic Range
Procedure of measuring and monitoring the drug concentration in plasma at different time intervals is called thisTherapeutic Drug Monitoring
Below this range, the drug is not effective and the patient begins having symptoms again. Above this range the drug has bad or toxic side effects that you want to avoidTherapeutic Range
Antiepileptics, Cardiac drugs, Aminoglycosides antibiotics and Lithium require thisTherapeutic Drug Monitoring
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Question Answer
When a constant fraction (or percentage) of the drug is absorbed, distributed or eliminated per unit timeFirst Order Kinetics
When a constant amount of the drug is absorbed, distributed or eliminated per unit timeZero Order Kinetics
Any drug that is given in extremely, excessively high doses can switch to this kineticsZero Order Kinetics
Phenyton and aspirin in low to mid therapeutic doses follows this kineticsFirst Order Kinetics
Phenyton and aspirin in high therapeutic doses follows this kineticsZero Order Kinetics
All drugs in toxic doses will follow this kineticsZero Order Kinetics
Alcohol always follows this kinetics regardless of amountZero Order Kinetics
This drug always follows zero order kinetics regardless of amountAlcohol
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Question Answer
The pharmacokinetic parameter that gives a quantitative measure of drug absorption isBioavailability
The pharmacokinetic parameter that gives a quantitative measure of drug distribution isVolume of Distribution
The pharmacokinetic parameter that gives a quantitative measure of drug elimination isClearance
Extrapolation of the elimination curve to time zeroC [0]
The volume of the plasma (blood) cleared of the drug, in a unit timeClearance
If the drug is reabsorbed by the tubule that drug will have a clearance ____ than the GFRLess
If the drug is secreted by the tubule that drug will have a clearance _____ than the GFRMore
If the drug is this, the formula CL=Rate of Elimination/ Plasma ConcentrationNot Protein Bound
If the drug is this, the formula CL=GFR x free fraction (ff) is used to calculate clearanceProtein Bound
If the drug is protein bound, the formula GFR x free fraction (ff) is used to calculate thisClearance
Time required to reduce the plasma concentration of the drug to its half of its original valuePlasma Half-Life
The formula 0.693 x Vd / CL is used to calculate thisPlasma Half-Life
A drug is considered to be essentially eliminated from the body after this many half-lives5 Half-Lives
Dose / Concentration (zero time)Volume of distribution (Vd)
This is the desired or optimal plasma concentration required to have the clinical effects of a drugTarget Concentration
Clearance (CL) x Plasma Concentration (C[ss]) / Bioavailability (F)Maintenance Dose
Average plasma concentration of the drug is maintained without much fluctuation. This takes place when the rate of drug administration becomes equal to the rate of drug eliminationSteady State Plasma Concentration (Css)
The number of half-lives needed to achieve 50% of the steady state plasma concentration1 Half-Life
The number of half-lives needed to achieve 100% of the steady state plasma concentration5 Half-Lives
A large dose given initially to get the drug levels up to a target concentration rapidlyLoading Dose
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Question Answer
0.693xVd/CLHalf Life
D/CVd
D= Vd x CLoading Dose
CL x Css /FMaintenance dose (MD)
Ko = Cl x CssRate of infusion
AUC[PO] / AUC[IV]Bioavailability (F)
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Pharmacodynamics

Question Answer
The study of drug effects inside the bodyPharmacodynamics
Aspirin inhibiting cyclooxygenase which inhibits prostaglandins synthesis is an example fo this type of drug actionEnzyme Action
Radioactivity - 131 Iodine and Osmotic activity - Mannitol are examples of this type of drug actionPhysical Action
Antacids - neutralizes gastric acid and chelating agents - inactivates toxic metals are examples of this type of drug actionChemical Action
The ability of the drug to combine with the receptorsAffinity
The ability of the drug to activate and induce a conformational change in the receptor after occupying the receptorIntrinsic Activity
Both affinity and maximal intrinsic activity. The drugs that bind and interact with a receptor, thereby initiate a chemical reaction inside cell and produces effectAgonist
Only the affinity but no intrinsic activity. A drug that binds to the receptor but can not activate it. It blocks the effect of an agonist for that receptorAntagonist
Any drug that binds to a receptor and produces an opposite effect as that of an agonist. Will have affinity and negative intrinsic activityInverse Agonist
Will have affinity but submaximal intrinsic activity. When given alone the partial agonist activates receptor to produce an effect. However less response than a full agonist. When given along with an agonist, it will block the agonist action.Partial Agonist
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Question Answer
The initial combination of drug with the receptor resulting in conformational changes in cellDrug Action
The ultimate change in biological function as a consequence of drug actionDrug Effect
A series of intermediate steps between drug action and drug effectTransducer Mechanism
ACh and GABA are examples of this receptor bindingLigand-Gated Ion Channels Receptors
Epinephrine and Histamine are examples of this receptor bindingG-Protein Coupled Receptors
Insulin is an example of this receptor bindingKinase-Linked Receptors
Steroids, Vitamin A, D, and Thyroxin are examples of this receptor bindingIntracellular Receptors
This is manifested as increased cardiac contractility, relaxation of smooth muscle, lipolysis, glyconeogenesiscAMP Pathway
Contraction of smooth muscle, secretion and transmitter release, neuronal excitability, cell proliferationIP3-DAG Pathway
Stimulates adenylyl cyclase and increases cAMP production and opens Ca2+ channelsGs Activation
Inhibits adenylyl cyclase and decreases cAMP productionGi Activation
Activates phospholipase CGq Activation
Beta 1, Beta 2, D1, H2 and 5HT-4 receptors use this protein for signal transductionGs G-Protein
Alpha 2, M2 receptors use this protein for signal transductionGi G-Protein
M1, M3, Alpha 1 and 5HT-1 use this protein for signal transductionGq G-Protein
Sigmoid shaped curve that has the dose versus effectDose Response Curve
On a Dose Response Curve, the height of the curve tells this about the drugEfficacy of the Drug
On a Dose Response Curve, the slope of the curve tells this about the drugRate of Action of the Drug
The point at which an increase in dose does not produce an increase in effect on a Dose Response CurvePlateu
It refers to the amount of drug needed to produce the responsePotency
Dose required to produce half the maximum response is used as an index to determine the potencyED[50]
ED[50] is the index measure of thisPotency
Moderate increase in dose leads to more increase in responseSteep DRC
Moderate increase in dose leads to little increase in response Flat DRC
Dose required to kill 50% of the subjectsLD[50]
Ratio of LD[50] / ED[50]Therapeutic Index (TI)
The dosage range between the minimum effective therapeutic concentration or dose, and the minimum toxic concentration or doseTherapeutic Window
Gap between therapeutic effect DRC and adverse effect DRC defines thisSafety Margin
When two drugs are given together or in quick succession nothing happensIndifferent
When two drugs are given together or in quick succession action of one drug is facilitated by the otherSynergism
When two drugs are given together or in quick succession action of one drug may decrease or inhibit the action of other drug Antagonism
Increase in the number of receptors on the surface of target cells, making the cells more sensitive to a hormone or another agentUp Regulation
This regulation is generally seen with use of antagonistsUp Regulation
Decrease in number of receptors on the surface of target cells, making the cells less sensitive to a hormone or another agentDown Regulation
This regulation is generally seen with prolonged & frequent use of short acting agonistsDown Regulation
Gradual reduction in response to drugs and the requirement of higher dose to produce a given response over a period of timeTolerance
Activated Charcoal used in poisoning, which adsorbs the poison material ,later get excretedPhysical Antagonism
Chelating agents used in metal poisoning, forms insoluble complexes with metals which can be excreted. Antacids used in acid peptic diseasesChemical Antagonism
Also called as functional antagonism. Two drugs act on different receptors and produce opposite effects on same physiological systemPhysiological antagonism
Two molecules competing for receptorReceptor Mediated Antagonism
Receptor mediated antagonism that is reversibleCompetitive
Receptor mediated antagonism that can be reversible or irreversibleNoncompetitive
Antagonist reversibly bind to receptors at the same binding site (active site) as the agonistCompetitive Antagonism
The antagonist irreversibly covalently binds to the active site of the same receptor changing the receptor conformationIrreversible Non-Competitive Antagonism
The antagonist reversibly binds to an allosteric site of the receptor changing the receptor conformationReversible Non-Competitive Antagonism
An increase in receptor number is calledUpregulation
A decrease in receptor number is calledDownregulation
Prolong use of antagonists may lead toUpregulation
Prolong use of agonists may lead toDownregulation
Gradual reduction in response to drugs over time or the requirement of higher dose to produce a given responseTolerance
Rapid desensitization to a drug produced by inoculation with a series of small frequent doses. A rapidly decreasing response to a drug following its initial administrationTachyphylaxis
a maximal response can be elicited at a concentration that does not require the occupancy of all receptors in a cell or tissueSpare Receptors
Spare receptors increase the ________ to a drugSensitivity
Concentration of the drug required to bind 50% of the receptor sitesK[d]
The measure of the affinity of the drug molecule to the receptorK[d]
If EC50 is less than this, spare receptors are said to existK[d]
If this is less than Kd, spare receptors are said to existEC[50]
A genetically based, abnormal response to a drug. Most often, they are dose-dependent and they are linked to genetic polymorphism of drug metabolizing enzymesIdiosyncrasy
Prolonged apnea seen with this drug due to plasma cholinesterase deficiencySuccinylcholine
Malignant hyperthermia seen with general anesthetics especially this drugHalothane
Only after a previous sensitizing contact with the same drug or with another drug closely related in chemical structureCrossed Sensitization
Drugs ability to cause an abnormal development of the fetus or the appearance of malformations. Morphological damage as well as a functional damage. Both are generally irreversibleTeratogenicity
Consumption of alcohol during pregnancy. Consists of CNS dysfunctions (such as low IQ and microencephaly), slowness in growth, a cluster of facial abnormalities, and malformationsFetal Alcohol Syndrome
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ANS Introduction

Question Answer
Largely concerned with consciously controlled functions such as movement, respiration, and postureSomatic division
Largely autonomous (independent) in that its activities are not under direct conscious control. It is concerned primarily with visceral functions that are necessary for life - such as cardiac output, blood flow to various organs, digestionAutonomic Nervous System (ANS)
Division of ANS into sympathetic and parasympathetic is determined by thisLocation of Ganglion in Spinal Cord
Division of ANS originating from the cerval and sacral spinal cordParasympathetic
Division of ANS originating from the thoracic spinal cordSympathetic
Acetylcholine is the neurotransmitterCholinergic Nerons
Adrenaline (Epinephrine ) or noradrenaline is the neurotransmitterAdrenergic/noradrenergic
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