Ch. 1-4 Flashcards Preview

Pharmacology > Ch. 1-4 > Flashcards

Flashcards in Ch. 1-4 Deck (21):
1

3 Most Important Properties of an Ideal Drug

1. effectiveness: most important
2. safety: no harmful effects
3. selectivity: drug elicits only the response for which it is given

2

5 Rights

1. drug
2. patient
3. dose
4. time
5. route

3

Pre-admin Assessment

- collection of baseline data to evaluate therapeutic and adverse effects
- identify high--risk patients
- assess of patient's capacity for self-care

4

Application of Pharm in Patient Care

- pre-admin assessment
2. dosage and admin
3. evaluating and promoting therapeutic effects
4. minimizing adverse effects
5. minimizing adverse interactions
6. making PRN decisions
7. manage toxicity

5

P-glycoprotein

- transports a wide variety of drugs out of cells

6

Passage of Drugs Across Membranes

- to directly penetrate, must be lipophilic
- polar molecules: uneven distribution of a charge; no net charge
- ions: molecules that have a net electrical charge
- Quats: contain at least one atom of nitrogen and carry a positive charge at all times
- pH-dependent ionization: acid is proton DONOR (ionize in basic media); base is a proton ACCEPTOR (ionize in acidic media)

7

Ion Trapping

- acidic drugs accumulate on alkaine side
- basic drugs accumulate on acidic side

8

Absorption

- rate= how soon effects will begin
- amount= how intense the effects will be
- rate of diffusion, surface area, blood flow, lipid solubility, and pH partitioning

9

First Pass Effect

- metabolism of a drug and its passage from liver into circulation
- ex. oral route- could be extensively metabolized by liver before reaching the systemic circulation
- ex. IV bypasses liver, preventing first-pass effect and more drug reaches circulation

10

Distribution

- blood flow to tissues
- exiting the vascular system
- entering cells

11

Blood Flow to Tissues

- blood flow determine rate of delivery
- abscesses and tumors: low regional blood flow affects therapy, pus-filled pockets rather than internal blood vessels, solid tumors have a limited blood supply

12

Exiting Vascular System

- typical capillary beds: drugs pass between capillary cells rather than through

13

BBB

- tight junctions
- lipid soluble or have a transport system can cross BBB

14

Placental Drug Transfer

- membranes do NOT constitute an absolute barrier
- birth defects: mental retardation, gross malformations, low birth weight

15

Protein Binding

- can form reversible bonds with proteins
- albumin is most abundant; large molecule always remains in blood stream

16

Entering Cells

- binding with receptors on external surface of cell membrane
- do not need to cross the membrane to act

17

Hepatic Drug-Metabolizing Enzymes

- most that takes place in liver, also known as P450 system
- does not always result in a smaller molecule

18

Therapeutic Consequences of Drug Metabolism

- accelerated renal drug excretion
- drug inactivation
- increased therapeutic action
- activation of prodrugs
- increased or decreased toxicity

19

Enterohepatic Recirculation

- repeating cycle in which drug is transported
- limited to drugs that have undergone glucronidation

20

Renal Routed of Drug Excretion

- glomerular filtratoin, passive tubular reabsorption, active tubular secretion
- factors that modify renal drug excretion: pH-dependent ionization, competition for active tubular transport, and age

21

Time Course of Drug Response

- Plasma drug levels: minimum effective concentration and toxic concentration (therapeutic range)
- single-dose time course: duration of effects is determined by the combination of metabolism and excretion; for drug levels to min. effective dose, therapeutic response will be maintained
- drug half-life: time required for the amount of drug in the body to decrease by 50%, percentage vs. amount, determine the dosing interval
- drug levels produced with repeated doses: plateau drug levels are achieved, time to plateau, techniques for reducing fluncuations in drug levels, loading doses vs maintenance doses, and decline from plateau