Karteikarten
Introduction to pharmacology
Karten in diesem Stapel (46)
- 1Define the term pharmacologythe study of substances that interact with living systems through chemical processes
- 2How do substances interact with living things?by binding to regulatory molecules and activating or inhibiting normal body processes
- 3Define the term drugany substance that interacts with a molecule or protein that plays a regulatory role in living organisms
- 4Define the term poisondrugs that have almost exclusively harmful effects
- 5Define the term toxinspoisons of biological origin, usually synthesised by plants or animals
- 6Define the term receptora specific molecule, usually a protein that interacts with a specific chemical causing a change in the receptor that produces a regulated function
- 7Define the term agonistany drug that binds to a receptor and activates the receptor
mimics the natural ligand of the receptor - 8What is the difference between agonists and antagonists?agonists initiate changes in cell function, producing effects of various types whereas the latter bind to the receptor without initiating such changes
- 9What happens when the ligand leaves the receptor?this usually deactivates the receptor and stops effect
although some receptors are permanently activated even after ligand has gone
(covalent change in receptor) - 10Define the term partial agonistbinds to receptor at active site but produces only a partial response, even when all receptors are occupied
have intermediate efficacy so produce only submaximal effects - 11Define the term efficacythe ability once bound to initiate changes that lead to effects
the >effect the more efficacious the drug
a.k.a intrinsic activity - 12Define the term affinitytendency to bind to receptors
- 13What sort of affinity do partial agonists have for the receptor? Explain the effects of thislower affinity for receptor
so don't bind as strongly as full agonist
have reduced intrinsic activity
occupies receptor so can prevent other agonists from binding - 14Describe how a partial agonist binds to and activates the receptorbinds to the receptor and activates it with a smaller shape change in the receptor that induces a partial receptor response
- 15Define the term pharmacologic antagonistany drug that binds to a receptor and prevents activation of the receptor
- 16State the names of the four different types of pharmacologic antagonistcompetitive
non-competitive
chemical
physiologic - 17How does a competitive antagonist work?fits into lock but does not activate receptor and competes for binding site
reduce agonist potency - 18How does a non-competitive antagonist work?binds to a site that is not the agonist binding site
modulates function of receptor
reduce agonist efficacy - 19How does a chemical antagonist work?binds directly to an agonist and prevents it binding to receptor
- 20What is a physiologic antagonist?when two substances have exactly opposite actions via different pathways
- 21What are the two ways drugs can be administered?oral or intravenous
oral - absorption then distribution (enteric transport, enteric metabolism)
intravenous - distribution (intravascular space, extravascular space, protein binding) - 22What two processes follow the distribution of drugs in the body?metabolism and elimination
metabolism - hepatic influx transport, phase I metabolism, phase II metabolism
elimination - biliary excretion, intestinal excretion or renal excretion - 23Define the terms enteric and effluxenteric - relating to or occurring in the intestines
efflux - the flowing out of a substance or particle - 24Define the terms intravascular and extravascularintravascular - situated or occurring within a blood vessel or blood vascular system
extravascular - situated or occurring outside the vascular system - 25What do drugs tend to be?weak acids or weak bases
- 26What is the difference between the dissociated and un-dissociated form of a drug?former is water soluble, later is lipid soluble
- 27What is meant by the term 'weak' acid? Use aspirin as an exampleincomplete dissociation in water
R-COOH --> R-COO- H+
acidic solution: >[H+], shifts p.o.e. to left, more R-COOH forms
alkali solution: >[OH-], shifts p.o.e to right, more ionic aspirin - 28What is meant by the term pKa?pH at which the drug is completely balanced between the uncharged (lipid soluble) and charged (water soluble) form
- 29What are other terms for fat-soluble and water-soluble?lipophilic
hydrophilic - 30What is TCA? What sort of acid is it? What are two damaging effects of TCA overdose?tricylic antidepressant
weak acid
causes cardiovascular and neurological toxicity - 31What should be done in the event of TCA overdose?give person activated charcoal to absorb TCA in GI tract
alkalinize the blood with sodium bicarbonate to change the drugs effect on the body
dissociates to charged form in alkaline solutions so doesn't diffuse back into blood from renal tubules - 32What is activated charcoal?normal charcoal heated in the presence of a gas, causing it to develop lots of internal spaces which can trap chemicals
- 33How can amphetamine excretion be speeded up?acidifying the urine by administration of ammonium chloride
- 34Explain what is meant by drug specificitydrug-receptor structure
drug solubility in water and the plasma membrane
receptor function - 35Explain what is meant by drug selectivitydrug's ability to preferentially produce a particular effect is related to the structural specificity of the drug binding to receptors
- 36What are receptors responsible for - specificity or selectivity of drug action?selectivity
- 37Drugs interact with receptors by means of chemical forces or bonds. What are the four different types? Comment on their relative strength alsocovalent - very strong and usually irreversible
electrostatic - fairly strong ionic groups and hydrogen bonds
lipophilic - weak
Van der waals -very weak - 38What is pharmacodynamics?actions of a drug on the body
e.g. propranolol lowers blood pressure and heart rate - 39What is pharmacokinetics?actions of the body on the drug (ADME)
e.g. propranolol is metabolised and eliminated by the liver and kidneys - 40Explain the shape of a standard dose response curveas dose increases response increases
as dose increases further response increment diminishes
dose reached in which no further increase in response; maximal response reached - 41What is half of a maximum response?EC50
half maximal effective concentration
(ED50 - dose)
the concentration of a drug which induces a response halfway between the baseline and maximum after a specified exposure time - 42What's the difference between the shape of a dose response curve with a competitive and non-competitive antagonist?competitive - need to add more drug to get to EC50
non-competitive - maximal effect reduced, EC50 same dose as for agonist alone - 43What is meant by the term potency?refers to concentration of a drug needed for that effect
have same efficacy - 44Explain what is meant by 'spare receptors'relationship between receptor occupancy and response is not linear
not all receptors need to be occupied to produce full response
so some receptors are 'spare' - 45What are two functional benefits of spare receptors?increase sensitivity and speed of a tissue's responsiveness to a ligand
- 46How are spare receptors useful with competitive antagonists?competitive antagonists shift the 'curve' to the right but the maximal effect can still be achieved by the agonist interacting with spare receptors
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- University Fundamentals of Medicine (Pharmacology) Karteikarten am Introduction to pharmacology, erstellt von Ifeoma Ezepue am 20/10/2015.
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- Ifeoma Ezepue
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