8-4 Principles of Pharm Flashcards
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A: [Acute Coronary Syndrome] = Unstable angina that involves occlusion of coronary artery and manifest as chest pain. Often caused by inoculated platelets.
B: This Dz can be augmented by Anti-platelet ASA (which also treats stroke & is an analgesic
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A: Drugs that affect smooth muscle cells = Musculotropic
- Histamine / serotonin / [ergot alkaloids]
- Vasoactive peptides
- NO donors and inhibitors
- Bronchodilators
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Drugs have a molecular wt ranging from
[7 daltons (Lithium) - 100,000 daltons]
B: Drugs can come from
- Microbes (such as Penicillin)
- Plants (ASA)
- Animals (insulin)
- Inorganic elements
- Synthetic organic compounds
- Synthetic organomimetics (Designer Drugs)
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Drug Formulations:
- Liquid
- Tablets
- Suppositories
- Sprays & inhalants
- Ointments
- Transdermal patches
- Drug coated medical devices
- Drug Implants
- Micro & nanoparticles
- Targeted Drug Delivery
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A: How do drugs move in the body? Permeation -Aqueous Diffusion -Lipid diffusion -Transport by special carriers -Endocytosis
B: Fick’s Law of Diffusion (CAP) predicts RATE drugs will cross a barrier.
(C1 - C2) x Area x [(Permeability coefficient) / (Thickness)]
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C: pH of the medium determines the fraction of [ionized charged] drugs vs. [unionzed UNcharged] drugs that can cross. If pK of the drug and pH of medium are known, ionized drug diffusion rate can be predicted using [Henderson-Hasselbalch]
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A: ABSORPTION of Drugs Depends on these 3…
(Route)
- IV
- IM
- SubQ
- Buccal & sublingual
- Rectal
- Inhalation
- Transdermal
- Other
(Blood Flow)
(Concentration)
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D: DISTRIBUTION depends on
- Size of Organ
- Blood Flow (just like Absorption)
- Solubility
- Binding (Some drugs bind to proteins–>makes the drug inActive. This is Reversible)
D2: Apparent Volume of Distribution = LARGER than physical volume because it includes other sites such as bone / capillaries / fat. “A for All”
vs.
[Physical Volume of Distribution] = only vascular compartment (think IV)
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M: METABOLISM can terminate OR activate a drug.
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E: Elimination of Drugs :
E1: 1st Order = Rate of elimination is proportional to concentration of drug in the system. HIGH Concentration = HIGH Elimination. 1st ORDER IS THE MORE COMMON DRUG EXCRETION IN THE BODY
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E: Elimination of Drugs :
E2: zero order = rate of drug elimination IS CONSTANT regardless of what the drug concentration is. not common
During zero order drug elimination graph will show LINEAR DEC in plasma concentration since elimination is constant
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MULTICOMPARTMENT DISTRIBUTION
A: In this model, MOST drugs undergo initial distribution and then undergo a slow elimination phase that is mathematically represented by the 2 compartment model.
B: Graphically, After an IV bolus the first Distribution phase will be curvilinear (alpha)… and then followed by a pure [multiexponential slow elimination phase (beta)]
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single compartment distribution
A: some drugs behave as if they are distributed to only 1 compartment (the vascular compartment)
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A: Drugs can bind to receptors with various bonds including covalent, electrostatic and weak bonds (hydrophobic / Van der Waals / hydrophilic)
B: Receptors:
-Type 1 = Plasma membrane receptors (AcH and NorEpi)
-Type 2= Cytoplasmic receptors (Steroid hormones)
C1: Agonist= Drug that can fully activate an effector system when it binds to a receptor
D: There are some drugs that DO NOT REQUIRE RECEPTORS
1. Volatile Anesthetics
2. Metal chelating agents
3. Osmotic diuretics
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A: DOWN-regulation= pharmacodynamic tolerance/desensitization caused by repeated administration of catecholamines—> DEC in # of alpha-receptors
C: Myasthenia Gravis = Antibodies form against AcH receptor motor-end plates
or
Familial Hypercholesterolemia= DEC # of plasma LDL receptors
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A: ANTagonist= BLOCKS THE AGONIST with structural similarity and does not cause same molecular change in receptor
A1: Competitive Antagonism= Reversible competition for agonist receptor WITHOUT inducing a biological response
A2: Non-Competitive Antagonism= iRReversible binding with receptor that prevents agonist from binding to receptor (ex: DFP combines with acetylcholinesterase to prevent AcH from binding to acetylcholinesterase—> HIGH LEVELS OF AcH
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AA: DRUG NOMENCLATURE
1st: Chemical Name = based on orgo chemistry
2nd: Code name= assigned to drug by the pharmaceutical manufacturer
3rd: [Generic NonProprietary name] = occurs when drug is admitted to U.S.. In pharmacopoeia the [Generic NonProprietary name] is the OFFICIAL name of the drug
4th: [Proprietary Tradename] (usually followed by a TM or superscript R)
B: The physician is allowed to indicate manufacturer for a generic drug and should write “no substitution” on the script if pt requires [Proprietary Tradename].
C:
*Chemical Equivalence= Related to amount of drug per tablet
- Biological equivalence= Related to pharmacokinetics involving bioavailability
- Therapeutic equivalence= Related to clinical response that will provide same efficacy & toxicity (hopefully less toxicity)
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DRUG TESTING &; APPROVAL
0 phase: Pre-clinical testing and toxicology screen
1st: Phase 1 = 10 normal volunteers receive small dose & are observed for efficacy & safety
2nd: Phase 2= Small group of pts with dz are observed for efficacy & safety
3rd: Phase 3= LARGE-scale clinical trial containing pts with dz who are observed for best dosage for tx of dz
4th: NDA (New Drug Application)= If FDA approves NDA, drug goes on market for general usage
