copyright (c) pearson education 2010 drugs, behavior, and modern society sixth edition charles f....

Copyright (c) Pearson Education 20Copyright (c) Pearson Education 201010

Drugs, Behavior, and Modern Society Drugs, Behavior, and Modern Society SIXTH EDITIONSIXTH EDITION

Charles F. LevinthalCharles F. Levinthal

Chapter 3Chapter 3How Drugs Work in the Body How Drugs Work in the Body

and on the Mindand on the Mind

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ROUTES OF DRUG ROUTES OF DRUG ADMINISTRATIONADMINISTRATION

• Injection (intravenous, intramuscular, Injection (intravenous, intramuscular, or or subcutaneous injection)subcutaneous injection)

• Inhalation (smoking)Inhalation (smoking)• Oral administration (by mouth)Oral administration (by mouth)• Absorption through the skin or Absorption through the skin or

membranes (intranasal sniffing, membranes (intranasal sniffing, sublingual absorption, rectal sublingual absorption, rectal suppository, transdermal patch)suppository, transdermal patch)


ELIMINATION HALF-LIFEELIMINATION HALF-LIFE

• A drug’s elimination half-life refers to A drug’s elimination half-life refers to the length of time it takes for the drug the length of time it takes for the drug to be reduced to 50 percent of its to be reduced to 50 percent of its equilibrium level in the bloodstream.equilibrium level in the bloodstream.

• Elimination half-life ofElimination half-life of nicotine --- a few hoursnicotine --- a few hours

cocaine --- a few hourscocaine --- a few hoursmarijuana --- much longermarijuana --- much longer


TIME-RELEASE DRUGS ARE TIME-RELEASE DRUGS ARE FORMULATED TO STAY WITHIN THE FORMULATED TO STAY WITHIN THE

THERAPEUTIC WINDOW FOR SEVERAL THERAPEUTIC WINDOW FOR SEVERAL HOURSHOURS


FORMS OF DRUG INTERACTIONFORMS OF DRUG INTERACTION

• Additive interaction (additivity)Additive interaction (additivity)

• Hyperadditive (synergistic) interactionHyperadditive (synergistic) interaction

• Potentiation (a special kind of Potentiation (a special kind of synergism)synergism)

• Antagonistic interactionAntagonistic interaction


Additive effect: If the effect of one Additive effect: If the effect of one drug alone is equivalent to a 4 and drug alone is equivalent to a 4 and the effect of another is a 6, then the the effect of another is a 6, then the combined additive effect is 10.combined additive effect is 10.

Hyperadditive/synergism: the Hyperadditive/synergism: the combined effects exceed the sum of combined effects exceed the sum of the individual drugs administered the individual drugs administered alonealone


Potentiation: one drug combined with Potentiation: one drug combined with another drug produces an enhanced another drug produces an enhanced effect when one of the drugs alone effect when one of the drugs alone would have no effectwould have no effect


EXAMPLES OF HYPERADDITIVE DRUG EXAMPLES OF HYPERADDITIVE DRUG INTERACTIONSINTERACTIONS

• Alcohol with sleep medications, Alcohol with sleep medications, insulin, painkillersinsulin, painkillers

• Headache remedies with CoumadinHeadache remedies with Coumadin• Lanoxin with licoriceLanoxin with licorice• Lanoxin with bran and oatmealLanoxin with bran and oatmeal• Tagamet with CoumadinTagamet with Coumadin


EXAMPLES OF ANTAGONISTIC DRUG EXAMPLES OF ANTAGONISTIC DRUG INTERACTIIONSINTERACTIIONS

• Morphine with naloxone or Morphine with naloxone or naltrexonenaltrexone

• Norpramin or related antidepressants Norpramin or related antidepressants with bran or oatmealwith bran or oatmeal

• Soy products with CoumadinSoy products with Coumadin• Broccoli, cabbage and asparagus Broccoli, cabbage and asparagus

with Coumadinwith Coumadin


CROSS-TOLERANCECROSS-TOLERANCE

Cross-tolerance results from the chronic Cross-tolerance results from the chronic use of one drug inducing a tolerance use of one drug inducing a tolerance effect with regard to a second drug effect with regard to a second drug that has never been used before.that has never been used before.

Example: alcohol with barbiturates or Example: alcohol with barbiturates or other depressant drugsother depressant drugs


NAME ALL THE DRUGS THAT WOULD NAME ALL THE DRUGS THAT WOULD SHOW CROSS TOLERANCE SHOW CROSS TOLERANCE

TO EACH OTHER. TO EACH OTHER. WHICH ONES WOULD NOT?WHICH ONES WOULD NOT?


CROSS-DEPENDENCECROSS-DEPENDENCE

Cross-dependence results from one Cross-dependence results from one drug substituting for whatever drug substituting for whatever physiologicl effects have been physiologicl effects have been produced by a second drug that has produced by a second drug that has been discontinued.been discontinued.


SOURCES OF INDIVIDUAL SOURCES OF INDIVIDUAL DIFFERENCES IN DRUG DIFFERENCES IN DRUG

RESPONSESRESPONSES

•Body weightBody weight

•GenderGender

•Ethnic backgroundEthnic background

•Expectations of the drug userExpectations of the drug user


THE ORGANIZATION OF THE THE ORGANIZATION OF THE NERVOUS SYSTEMNERVOUS SYSTEM


SYMPATHETIC AND PARASYMPATHETIC SYMPATHETIC AND PARASYMPATHETIC BRANCHES OF THE BRANCHES OF THE

AUTONOMIC NERVOUS SYSTEMAUTONOMIC NERVOUS SYSTEM


THREE MAJOR DIVISIONS OF THE THREE MAJOR DIVISIONS OF THE BRAINBRAIN

• Hindbrain --- medulla, pons, Hindbrain --- medulla, pons, cerebellumcerebellum

• Midbrain --- substantia nigraMidbrain --- substantia nigra

• Forebrain --- hypothalamus, limbic Forebrain --- hypothalamus, limbic system, cerebral cortexsystem, cerebral cortex


STRUCTURES OF THE HUMAN STRUCTURES OF THE HUMAN BRAINBRAIN


BASIC STRUCTURES OF A NEURONBASIC STRUCTURES OF A NEURON


THE SEQUENCE OF EVENTS THE SEQUENCE OF EVENTS IN SYNAPTIC COMMUNICATIONIN SYNAPTIC COMMUNICATION


COMMUNICATION BETWEEN NEURONS COMMUNICATION BETWEEN NEURONS DEPENDS ON A “MATCH” BETWEEN DEPENDS ON A “MATCH” BETWEEN

NEUROTRANSMITTER AND RECPETORNEUROTRANSMITTER AND RECPETOR


SEVEN MAJOR SEVEN MAJOR NEUROTRANSMITTERSNEUROTRANSMITTERS

• AcetylcholineAcetylcholine• NorepinephrineNorepinephrine• DopamineDopamine• SerotoninSerotonin• Gamma aminobutyric acid (GABA)Gamma aminobutyric acid (GABA)• GlutamateGlutamate• EndorphinsEndorphins


Drug Effects and Synaptic Drug Effects and Synaptic Communication in the Nervous SystemCommunication in the Nervous System


TWO BIOCHEMICAL PROCESSES TWO BIOCHEMICAL PROCESSES UNDERLYING DRUG TOLERANCE UNDERLYING DRUG TOLERANCE

• Cellular (pharmacodynamic) tolerance Cellular (pharmacodynamic) tolerance

--- through changes in synapses of --- through changes in synapses of neuronsneurons

• Metabolic (dispositional) tolerance Metabolic (dispositional) tolerance

--- through changes in --- through changes in biotransformation in biotransformation in the the liverliver


normal subject

cocaine abuser (1 month post)

cocaine abuser (4 months post)

Effect of Cocaine Abuse on Dopamine D2 Receptors

PET SCANS SHOWING DOPAMINE PET SCANS SHOWING DOPAMINE ACTIVITY IN THE BRAINS OF A DRUG-ACTIVITY IN THE BRAINS OF A DRUG-

FREE SUBJECT AND A COCAINE FREE SUBJECT AND A COCAINE ABUSER AT TWO STAGES OF COCAINE ABUSER AT TWO STAGES OF COCAINE

USEUSE


A DRUG EFFECT A DRUG EFFECT AS A THREE-WAY INTERACTIONAS A THREE-WAY INTERACTION


DRUG RESEARCH PROCEDURESDRUG RESEARCH PROCEDURES

• Testing the effectiveness of a drug Testing the effectiveness of a drug against a no-treatment condition ---against a no-treatment condition ---WRONGWRONG

• Testing the effectiveness of a drug Testing the effectiveness of a drug against an active placebo --- RIGHTagainst an active placebo --- RIGHT


DOUBLE-BLIND PLACEBO DOUBLE-BLIND PLACEBO CONTROL DESIGNCONTROL DESIGN

• Individuals administering the drug do Individuals administering the drug do not know whether the substance not know whether the substance administered is actually the drug or a administered is actually the drug or a placebo.placebo.

• Individuals receiving the drug do not Individuals receiving the drug do not know whether the substance received is know whether the substance received is actually the drug or a placebo.actually the drug or a placebo.

copyright (c) pearson education 2010 drugs, behavior, and modern society sixth edition charles f....

Documents

individual drugs

drugs work

tolerance effect

timerelease drugs

combined additive effect

enhanced effect

cross tolerance

tolerance results