exam 1

Question 1

Pharmacodynamics what is it?

Answer 1

mech by which drugs interact( molecular level) with constituents of cells or cellular environments to produce biochemical and/or physiological changes in cells, tissues, organs, and ultimately patients-Different drugs have different biological targets. Understanding how each drug influences its targets is an essential component of any pharmacotherapeutic plan of medication management

Question 2

Non-Specific Physio-Chemical Drug Action

Answer 2

Do not produce any direct effect on cells but can alter the functioning of cells by indirectly affecting the cell’s environment.

Question 3

5 mechanisms by which drugs can alter the physical or chemical environment of cells

Answer 3

1- ALTERATION OF BODY CHEMISTRY
2- ADSORPTION OF TOXINS, ELECTROLYTES, BILE SALTS, AND OTHER DRUGS IN THE INTESTINAL TRACT
3- IMPOSITION OF A PHYSICAL BARRIER(sunblock)
4-LUBE
5- ALTERATION OF SURFACE TENSION

Question 4

Do drugs make receptors?

Answer 4

NO drugs “borrow” them for a time from the body’s own natural physiologically active substances. The interaction of the drug with the active site on the receptor’s external extension has the same or similar effect as the body’s own natural substance

Question 5

Drug-Receptor Binding

Answer 5

The interaction between a drug and its specific receptor. This binding between drug and receptor is only temporary

Question 6

Drug-Receptor Affinity

Answer 6

Degree of attraction (electromagnetic force) between a drug molecule and its receptor molecule
Drug-receptor affinity bears a very close relationship to drug potency.

Question 7

AGONIST DRUGS

Answer 7

mimic the actions of the body’s endogenous biomediators on their receptors. They have both affinity for and intrinsic activity on these receptors

Question 8

Agonist I

Answer 8

Agonist drugs which bind to the same molecular extracellular site on the receptor as the endogenous biomediator
EX-Epi, opioids

Question 9

Agonist II

Answer 9

Agonist drugs which bind to a different molecular extracellular site on the receptor than the endogenous biomediator but, by binding to the receptor, enhance the effect of the endogenous biomediator on its own receptor ex-benzos

Question 10

ANTAGONIST DRUGS

Answer 10

Drugs which prevent (or block) the actions of the body’s endogenous biomediators (or other agonist drugs) on their receptors. Antagonist drugs have affinity for receptors but lack intrinsic activity on them. They work by occupying the receptor, having no action of their own, but prevent occupancy of the receptor by the natural endogenous biomediator.

Question 11

Antagonist I

Answer 11

bind to the same molecular extracellular site on the receptor as the natural biomediator and diminish (inhibit) or prevent (block) the action of the natural compound. Examples are atropine and the H 2 receptor blockers.

Question 12

Antagonist II

Answer 12

bind to a different molecular extracellular site from the endogenous biomediator and partially inhibit the action of the natural compound. Examples are calcium channel blockers.

Question 13

Antagonist III

Answer 13

translocate through the plasma membrane and inhibit the receptor’s signal on the inside of the cell, either at the internal part of the receptor or some other secondary messenger mechanism inside the cell. Examples are milrinone (Primacor), phosphodiesterase inhibitors (theophylline), and Viagra.

Question 14

Cont use of agonist drug administration results in

Answer 14

down-regulation of receptors

Question 15

continuous use of antagonist drugs results in

Answer 15

up-regulation of receptors

Question 16

log dose-response curve

Answer 16

demonstrates the dosage range that will most likely produce the desired degree of response for each drug. The curve is an S-shaped curve

Question 17

logarithm

Answer 17

a relationship between the dose of a drug and its effect and this relationship is expressed graphically by plotting the logarithm of the dose of a drug against the magnitude of its effect.

Question 18

Clinical Uses of Log Dose-Response

Answer 18

Shows therapeutic effect range

Question 19

EFFECTIVE DOSE

Answer 19

50% the dose exactly in the center of this clinically useful range is defined as that dose which produces one half of the clinically desired effect

Question 20

LETHAL DOSE

Answer 20

the dose in the center of the curve can be identified and is labeled as the lethal dose - 50% or the LD50. The LD50 is defined as that dose of a drug which produces death in one half of the test animals to which it is administered

Question 21

drug’s therapeutic index

Answer 21

Dividing the LD50 by the ED50 results in a number (without a label) that is referred to as a drug’s therapeutic index

Question 22

Whats another use of the log dose-response curve

Answer 22

compare the relative potencies and efficiencies of two different drugs

Question 23

What is pharmacokinetics

Answer 23

mechanisms by which the body handles (processes) drugs
4 processes; absorption, distribution, metabolism, and excretion

Question 24

metabolism and excretion

Answer 24

drug clearance. It is the disappearance of the administered drug (the parent drug) from the patient’s serum.

Question 25

absorption

Answer 25

how much of the administered dose of the drug actually gains entry into the patient’s body-process by which drug molecules move from their site of administration, across one or more cell membranes, in order to gain entry into the blood.

Question 26

distribution

Answer 26

how many drug molecules reach their target cell receptors

Question 27

Determinants of Absorption

Answer 27

1-THE SOLUBILITY (OR DISSOLVABILITY) OF THE DRUG( ex-fastest liquid, slowest-SR drugs)
2-PHYSICAL PROPERTIES OF THE DRUG
3- THE AREA OF THE ABSORPTIVE SURFACE
4- BLOOD SUPPLY AT THE ABSORPTIVE SURFACE
5- LENGTH OF TIME THE DRUG IS IN CONTACT WITH THE ABSORBING SURFACE

Question 28

2 forms of distribution

Answer 28

1. RAPID DISTRIBUTION
2. REDISTRIBUTION

Question 29

Determinants of Distribution

Answer 29

1-THE ADEQUACY OF SYSTEMIC BLOOD FLOW
2-SERUM PROTEIN BINDING (albumin)
3-TISSUE TRAPPING
4-PHYSIOLOGICAL BARRIERS(blood-brain-barrier and the placenta)

Question 30

Mechanisms of Drug Metabolism

Answer 30

main organ of drug metabolism is the liver but other sites at which drugs can be metabolized include the kidney, lungs, gastrointestinal mucosa, and nerve endings

Question 31

Metabolism phases

Answer 31

PHASE I -mediated in the liver (and some other organs) by the P-450 enzyme systems
PHASE II-reactions are mediated by a different series of enzymes called conjugases or transferases

Question 32

prodrug

Answer 32

in the form in which they are administered, have no pharmacological activity (i.e. they lack both affinity and intrinsic activity). The metabolic activity which the body performs on them actually changes the three dimensional structure to the point that they acquire pharmacological activity.

Question 33

First-Pass Effect

Answer 33

hepatic blood flow brings drug molecules to the liver cells, they are “extracted” from the blood by these hepatic cells. Once inside the cells, the drug molecules undergo varying degrees of biotransformation into their metabolites. As blood leaves the liver and enters the systemic circulation, the drug molecules are capable of interacting with their receptors and exerting their pharmacological effects

Question 34

Mechanisms of Excretion

Answer 34

(1) GLOMERULAR FILTRATION-Only free drug and free metabolites
(2) RENAL TUBULAR SECRETION-free drugs
(3) DISTAL RENAL TUBULAR REABSORPTION -

Question 35

two classifications of ADR’s

Answer 35

TYPE A: INTRINSIC ADVERSE DRUG REACTION-predictable, and are dose-dependent -most common
TYPE B: IDIOSYNCRATIC ADVERSE DRUG REACTION -uncommon, unpredictable

Question 36

TOXIC REACTION

Answer 36

severe drug reaction (often considered a drug poisoning) that is caused by either a quantitative or a qualitative overdose of the drug

Question 37

CHAIN REACTION

Answer 37

adverse reactions of one drug require “treatment” with another drug which can itself cause adverse reactions which can, in turn, require yet another drug for correction and so on

Question 38

CUMULATIVE REACTION

Answer 38

progressively increasing response to a drug dosage, given repeatedly, which is associated with progressively increasing serum levels of the drug. This occurs when the rate of absorption of the drug exceeds its rate of elimination and is commonly seen in patients with renal insufficiency in whom there is a decreased rate of excretion of the drug in the face of its continued administration.

Question 39

Requirements for Rational Drug Selection

Answer 39

1-ALWAYS BEGIN WITH A DIAGNOSIS
2-. UNDERSTAND THE PATHOPHYSIOLOGY OF THE MEDICAL DIAGNOSIS
3. REVIEW THE MENU OF PHARMACOTHERAPEUTIC OPTIONS
UNDERSTAND (I.E., HAVE KNOWLEDGE OF) “ALL THE POSSIBLE DRUGS” THAT COULD BE USED TO TREAT A SPECIFIC CONDITION AND ESTABLISH A PRIORITY RANKING FOR THEM
UNDERSTAND THE PHARMACODYNAMICS and PHARMACOKINETICS
4-UNDERSTAND POTENTIAL ADVERSE DRUG REACTIONS AND DRUG INTERACTIONS AND CONTRAINDICATIONS
5-ACQUIRE “ACCURATE” DRUG INFORMATION
PATIENt
6-ESTABLISH THERAPEUTIC GUIDELINES AND END-POINTS FOR DRUG THERAPY T-SPECIFIC DRUG AND DOSE
PREDICT, WITH REASONABLE CERTAINTY, THE EXPECTED COMPLIANCE BY THE PATIENT TO A CHOSEN PLAN OF THERAPY