Drug Administration And Absorption

Front 1

link between phrmacokinetics and pharmacodynamics?

Back 1

concentration: pharmacokinetics = dose-concentration and pharmacodynamics = concentration-effect

Front 2

definition of drug absorption?

Back 2

passage of drug from site of administration into circulation

Front 3

>80% of prescribed drugs are what class?

Back 3

enteral

Front 4

what drug characteristics are important to drugs administered orally?

Back 4

surface area, pH, particle size

Front 5

what drug characteristics are important to drugs administered sublingually?

Back 5

lipid solubility and pH

Front 6

what is main disadvantage of orally administered drugs?

Back 6

first pass effect may be significant

Front 7

advantages of IV administration?

Back 7

direct, easy to control dose for drugs with narrow margin of safety (small therapeutic range), reach desired blood level, for drugs which cannot be tolerated by other routes

Front 8

possible adverse effects of IV administration?

Back 8

anaphylactic reactions, embolism, hemolysis or agglutination of blood, infection

Front 9

what form of drug administration follows first order kinetics?

Back 9

intramuscular

Front 10

what is intramuscular drug administration limited by?

Back 10

blood flow, ionization, lipid solubility, molecular size

Front 11

what are limitations to subcutaneous drug administration?

Back 11

absorption may be retarded by cooling, vasoconstriction

Front 12

where is intrathecal injected to?

Back 12

subarachnoid space

Front 13

what limits pulmonary drug administration?

Back 13

particle sizes >2 microm is probably not absorbed

Front 14

requirements and advantages of topical application of drug?

Back 14

highly lipid soluble substances can be absorbed slowly through the skin

Front 15

how is lipid solubility determined?

Back 15

by lipid (oil)/water partition coefficient

Front 16

what does a higher oil/water partition coefficient indicate?

Back 16

hydrophobic and will more easily pass through biological membranes

Front 17

what does the degree of ionization depend on and what is the consequence?

Back 17

depend on pKa of drug and pH of the environment --> only nonionized particles can pass through membranes

Front 18

how can drugs move across cell membranes?

Back 18

passive diffusion, facilitated diffusion, active transport, endocytosis, exocytosis

Front 19

fick's law of diffusion defines flux as a function of what for passive diffusion?

Back 19

concentration gradietn, area, permeability coefficient, and thickness

Front 20

what does the pH partition hypothesis suggest?

Back 20

ion trapping mechanism due to differing pHs of body causing drug to exist in either nonionized or ionized form, which dictate if the drug will be able to cross the biological membranes

Front 21

for drugs with similar pKa, what can influence the amount of drug absorbed?

Back 21

increased lipid solubility results in greater absorption

Front 22

consequences of first pass effect?

Back 22

significantly decreased bioavailability of orally administered drugs and large individual variation in plasma concentration

Front 23

how does oral administration differ from sublingual/buccal and rectal administration of drug?

Back 23

blood from the intestinal mucosa drains into the liver via the hepatic portal system, whereas the blood from the mouth and rectum drains into the systemic circulation

Front 24

which drugs have poor availability when given orally due to first pass effect?

Back 24

acetylsalicyclic acid, chlorpromazine, desipramine, isoproterenol, propranolol, lidocaine, meperidine, methylphenidate, morphine, salicylamide, nitroglycerin, nortriptyline, pentazocine, propoxyphen