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Pharmacology - Final - Part 3

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davidwurbel7's version from 2016-08-14 19:09

Pharmacokinetics 1 - Drug Transportation

Question Answer
Most drugs permeate through cell membranes by thisDiffusion
Some drugs permeate through intercellular pores by thisFiltration
These drugs pass directly through the cell membraneLipid Soluble Drug
This problem can arise with transportation of drugs into the cell using facilitated diffusion and active transportSaturation
Drugs with high molecular weight use this method to enter a cellEndocytosis
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Pharmacokinetics 2 - Drug Absorption

Question Answer
Transport of a drug from its site of administration to the blood stream and to its site of actionAbsorption
The overall important factor governing drug absorptionLipid Solubility
This aspect of the patient is good to know that can change to absorption of the drugpH of Stomach
This property of a drug can change the absorption of the drugpKa
Determined by Ionization or non ionization status of the drugLipid Solubility
Nature of the drug - acid or a base, pH of the medium (Body compartment) and pKa of the drug are the three factors that affect this of a drugIonization
This state of a drug is better for the lipid solubility and absorption of a drugNon-Ionized State
This state of a drug is better for the lipid insolubility and excretion of a drugIonized State
An acidic drug becomes more this as the pH increaseIonized
A basic drug becomes more this as the pH increaseNon-Ionized
An acidic drug becomes more this as the pH decreasesNon-Ionized
A basic drug becomes more this as the pH decreasesIonized
An acidic drug is best absorbed in this type of environmentAcidic
A basic drug is best absorbed in the type of environmentBasic
The percentage of an acidic drug in this form increases as the pH of the environment increasesIonized
The percentage of a basic drug in this form increases as the pH of the environment increasesUn-Ionized
The pH at which 50% of the drug is ionized and 50% is unionizedpKa
For an acid drug, pH - pKa = logIonized / Non-Ionized
For a basic drug, pH - pKa = logNon-ionized / Ionized
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Pharmacokinetics 3 - Route

Question Answer
Most convenient ,usually the safest, least expensive, and most often used and self medication is possibleOral Route
The three limitations of this route include delayed effects, therefore not good for emergency, gastric irritation, and less bioavailabilityOral Route
If a drug is metabolized in the gut wall or in the liver, a fraction of the active drug will be eliminated during this before reaching the general circulationFirst Pass Metabolism
The pharmacokinetic parameter that gives a quantitative measure of drug absorptionBioavailability
AUC[PO] / AUC[IV]Bioavailability (f)
Three limitations of this route include delayed effects, therefore not good for emergency, gastric irritation and less bioavailabilityOral Route
The advantages of this route are immediate effect and good for emergency and 100% bioavailabilityIV Route
The disadvantages of this route are adverse effects will be more severe and immediateIV Route
This route used for many protein drugs and is commonly used for vaccinesSubcutaneous Route
This is the preferred route when larger volumes of a drug product are neededIntramuscular Route
Usually, this method is used to administer drugs that act on the lungs, such as aerosolized antiasthamatic drugs in metered-dose containersInhalational Route
The advantages of this route include immediate drug effect, by-passing of the First pass metabolism and the drug action can be terminated voluntarily at ones wish by spittingSublingual Route
The disadvantages of this route include erratic drug absorption which leads to unpredictable drug effects with respect to drug concentrationsSublingual Route
The advantages of this route include by-pass first pass metabolism in the liver and consciousness is not requiredRectal Route
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Pharmacokinetics 4 - Distribution

Question Answer
The extracellular fluid volume is14 L
The plasma fluid volume is4 L
The interstitial fluid volume is10 L
The intracellular fluid volume is28 L
The total body water volume is42 L
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Question Answer
The delivery of drug from systemic circulation into the tissueDistribution
The factors of size of organ, rate of blood flow, solubility, regional differences in pH and plasma protein binding affect this for a drugDistribution
The most important aspect of drug distribution is thisPlasma Protein Binding
If a drug is acidic it will most likely bind to this protein in the bloodAlbumin
If a drug is basic it will most likely bind to this protein in the bloodAlpha1-Acid-Glycoprotein
Drugs that are this in the plasma cannot cross the cell membrane, cannot be distributed, is not available for their action, cannot be filtered in kidney, is not available for metabolism, are known for drug-drug interactions and will have the least volume of distribution (Vd)Protein Bound
The volume apparently necessary to contain the amount of drug homogeneously at the concentration found in the bloodVolume of Distribution
Vd=D/C[0]Volume of Distribution Formula
This is expressed generally as Liters/70Kg body weightVolume of Distribution
This value is fixed for any given drugVolume of Distribution
The pharmacokinetic parameter that gives a quantitative measure of drug distribution is namedVolume of Distribution
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Pharmacokinetics 5 : Drug Metabolism

Question Answer
Chemical alteration of a drug in the body which converts the non polar lipid soluble compounds to more polar and water soluble and thus makes the drug more suitable for excretionDrug Metabolism
The organ that is most important for drug metabolism is this organLiver
The metabolite is active form of the original drugProdrug
Phase I reactions involved in drug metabolism areNon Synthetic Reactions
Phase II reactions involved in drug metabolism areSynthetic or Conjugation Reactions
Usually convert the Parent drug to more polar metabolite by introducing a functional group usually a –OH or -SHPhase I Reaction
Oxidation and Reduction reactions are examples of this reactionPhase I Reaction
Phase I metabolites couple with an endogenous substance to yield drug conjugatesPhase II Reaction
Isoniazid, hydralazine and procainamide undergo this type of Phase II reactionAcetylation
Acetaminophen undergo this type of Phase II reactionGlutathione Conjugation
Most drugs undergo this type of Phase II reactionGlucuronidation
Steroids undergo this type of Phase II reactionSulfation
Majority of the drugs metabolism involves oxidation reactions involves this enzymeCytochrome P 450
Most common subtype of cytochrome P 450CYP3A
Some drugs on repeated administration, can "induce" more CYP P450 enzymes in liverCYP 450 Induction
Anti-tuberculosis (Rifampin) and anti-convulsants (Barbiturates ,Phenytoin, Carbamazepine) as well as Glucocorticoids, and Alcohol chronic administration are examples of drugs known to cause thisCYP 450 Induction
Some drugs on repeated administration, can "reduction" more CYP P450 enzymes in liverCYP 450 Reduction
Cimetidine, SSRIs, Ketoconazole, Macrolide antibiotics, Fluoroquinolones, HIV protease inhibitors and Grapefruit juice are examples of drugs known to cause thisCYP 450 Reduction
Co-administered drugs, genetic variation, age and diseases are factors that affect thisDrug Metabolism
A genetic variation in individual's ability to metabolize the drugs which are acetylatedFast and Slow Acetylators
Acetylators that require a higher dose of a drug to be effectiveFast Acetylators
Acetylators that require a lower dose of a drug to prevent drug toxicitySlow Acetylators
Slow acetylators may develop adverse effects of Isoniazid, Hydralazine, Procainamide may develop thisDrug-Induced Lupus Erythematosus
Functions to expel drugs/foreign substances from the intestinal mucosa into the lumen and thus enhance their excretionP-glycoprotein (P-gp)
P-glycoproteins (P-gp) in certain cells (cancer) and in pathogens can lead to thisMulti-Drug Resistance (MDR)
P-gp is also found in these types of cellsMDR (Multi-Drug Resistant)-Cancer Cells
Passage of drugs from liver to intestine and intestine to liver is called thisEnterohepatic Cycling
Oral contraceptive pills, amphetamine, morphine, estradiol are examples of drugs undergo thisEnterohepatic Cycling
These types of drugs can interfere with enterohepatic circulation and reduce the activity of the drugAntibiotics
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