acamprosate moa - pk overview george f. koob, ph.d. professor, department of neuropharmacology...
TRANSCRIPT
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MOA - PK OverviewMOA - PK OverviewGeorge F. Koob, Ph.D.
Professor, Department of Neuropharmacology
Director, Division of Psychopharmacology
The Scripps Research Institute
George F. Koob, Ph.D.
Professor, Department of Neuropharmacology
Director, Division of Psychopharmacology
The Scripps Research Institute
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Stages of Alcoholism Important for the Development of Animal ModelsStages of Alcoholism Important for the Development of Animal Models
Acute Reinforcement/Social DrinkingAcute Reinforcement/Social Drinking
Escalating/Compulsive Use Binge Drinking
Escalating/Compulsive Use Binge Drinking
DependenceDependence
WithdrawalWithdrawal
Protracted WithdrawalProtracted Withdrawal
Recovery?Recovery?
Genetic variables
Environmental factors
Stress
Conditioning effects
Genetic variables
Environmental factors
Stress
Conditioning effectsRelapse
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Effects of Acamprosate on Animal Models of Excessive Drinking
Effects of Acamprosate on Animal Models of Excessive Drinking
Acamprosate decreases alcohol drinking in rats selected for excessive drinking (Boismare et al., 1984)
Acamprosate decreases alcohol intake in dependent rats(Le Magnen, Tran, Durlach and Martin, 1987)
Acamprosate reverses the preference for alcohol and the increase in drinking in dependent rats during withdrawal (Geiss, Heidbreder, Opsomer, Durbin and De Witte, 1991; Morse and Koob, unpublished results)
Acamprosate eliminates the alcohol deprivation effect in rats under free-drinking continuous access or operant limited access conditions (Spanagel, Holter, Allingham, Landgraf and Zieglgansberger, 1996; Holter, Landgraf, Zieglgansberger and Spanagel, 1997; Heyser, Schulteis, Durbin and Koob, 1998)
Acamprosate decreases alcohol drinking in rats selected for excessive drinking (Boismare et al., 1984)
Acamprosate decreases alcohol intake in dependent rats(Le Magnen, Tran, Durlach and Martin, 1987)
Acamprosate reverses the preference for alcohol and the increase in drinking in dependent rats during withdrawal (Geiss, Heidbreder, Opsomer, Durbin and De Witte, 1991; Morse and Koob, unpublished results)
Acamprosate eliminates the alcohol deprivation effect in rats under free-drinking continuous access or operant limited access conditions (Spanagel, Holter, Allingham, Landgraf and Zieglgansberger, 1996; Holter, Landgraf, Zieglgansberger and Spanagel, 1997; Heyser, Schulteis, Durbin and Koob, 1998)
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Protocol for Initiation of Lever Pressing for Oral Ethanol Self-Administration in
the Rat
Protocol for Initiation of Lever Pressing for Oral Ethanol Self-Administration in
the Rat
1-3
4-9
10
11-12
13
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15-16
17
18+
1-3
4-9
10
11-12
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15-16
17
18+
Days
Days
Day
Days
Day
Day
Days
Day
Day
Days
Days
Day
Days
Day
Day
Days
Day
Day
0.2%
0.2%
-
0.2%
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0.2%
-
0.2%
-
0.2%
0.2%
-
0.2%
-
0.2%
-
0.2%
-
0%
5%
5%
5%
5%
8%
8%
10%
10%
0%
5%
5%
5%
5%
8%
8%
10%
10%
TrainingTraining Saccharin (w/v)Saccharin (w/v) EtOH (w/v)EtOH (w/v)
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ACAMPROSATEACAMPROSATEFrom: Rassnick S, Pulvirenti L and Koob GF, Alcohol, 1993, 10:127-132.
Blood Alcohol Levels in a Free-Choice Operant Task for Ethanol (10%) and Water
Following the Saccharin Fade Out Procedure
Blood Alcohol Levels in a Free-Choice Operant Task for Ethanol (10%) and Water
Following the Saccharin Fade Out Procedure
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Effects of Abstinence Intervalon Alcohol Self-AdministrationEffects of Abstinence Interval
on Alcohol Self-Administration
From: Heyser CJ, Schulteis G, Durbin P and Koob GF, Neuropsychopharmacology, 1998, 18:125-133.
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Chronic Acamprosate on Responding for Ethanol Following 5 Days
Abstinence
Chronic Acamprosate on Responding for Ethanol Following 5 Days
Abstinence
From: Heyser CJ, Schulteis G, Durbin P and Koob GF,Neuropsychopharmacology, 1998, 18:125-133.
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What Acamprosate Does Not Do in Animal Models
What Acamprosate Does Not Do in Animal Models
Acamprosate does not produce anti-conflict effects in an animal model of anxiety (Koob and Britton, unpublished results)
Acamprosate does not substitute for alcohol in drug discrimination (Spanagel, Zieglgansberger and Hundt, 1996)
Acamprosate does not block the discriminative stimulus properties of alcohol (Spanagel, Zieglgansberger and Hundt, 1996)
Acamprosate does not have any reinforcing effects or aversive effects on its own (Grant and Woolverton, 1989; Morse and Koob, unpublished results)
Acamprosate does not antagonize the discriminative stimulus effects of amphetamine or morphine, or the reinforcing effects of heroin (Pascucci et al., 1999; Spanagel et al., 1998)
Acamprosate does not produce anti-conflict effects in an animal model of anxiety (Koob and Britton, unpublished results)
Acamprosate does not substitute for alcohol in drug discrimination (Spanagel, Zieglgansberger and Hundt, 1996)
Acamprosate does not block the discriminative stimulus properties of alcohol (Spanagel, Zieglgansberger and Hundt, 1996)
Acamprosate does not have any reinforcing effects or aversive effects on its own (Grant and Woolverton, 1989; Morse and Koob, unpublished results)
Acamprosate does not antagonize the discriminative stimulus effects of amphetamine or morphine, or the reinforcing effects of heroin (Pascucci et al., 1999; Spanagel et al., 1998)
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ACAMPROSATEACAMPROSATEFrom: Spanagel R and Zieglgansberger W, Trends Pharmacol Sci, 1997, 18:54-59.
Schematic Neuron Showing the Possible Mode of Action of Acamprosate on
Alcohol-Related Effects
Schematic Neuron Showing the Possible Mode of Action of Acamprosate on
Alcohol-Related Effects
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Neuropharmacological Effects of Acamprosate
Neuropharmacological Effects of Acamprosate
Acamprosate inhibits neuronal hyperexcitatability by decreasing presynaptic release of the excitatory neurotransmitter glutamate and by decreasing post-synaptic excitability of glutamate receptors (Zeise, Kaparaov, Capogna and Ziegelgansberger, 1993; Dahchour et al., 1998; Koob, Mason, De Witte, Littleton and Siggins, 2002)
Acamprosate inhibits calcium influx through NMDA glutamate receptors through an interaction with polyamines on the NMDA receptor (Naassila, Hammoumi, Legrand, Durbin and Daoust, 1998; al-Qatari, Bouchenafa and Littleton, 1998; Popp and Lovinger, 2000)
Acamprosate inhibits calcium influx through voltage-dependent calcium channels (al-Qatari and Littleton, 1995; Allgaier, Franke, Dobottka and Scheibler, 2000)
Acamprosate increases synaptic availability of the inhibitory neurotransmitter taurine (Dahchour, Quertemont and De Witte, 1996)
Acamprosate inhibits neuronal hyperexcitatability by decreasing presynaptic release of the excitatory neurotransmitter glutamate and by decreasing post-synaptic excitability of glutamate receptors (Zeise, Kaparaov, Capogna and Ziegelgansberger, 1993; Dahchour et al., 1998; Koob, Mason, De Witte, Littleton and Siggins, 2002)
Acamprosate inhibits calcium influx through NMDA glutamate receptors through an interaction with polyamines on the NMDA receptor (Naassila, Hammoumi, Legrand, Durbin and Daoust, 1998; al-Qatari, Bouchenafa and Littleton, 1998; Popp and Lovinger, 2000)
Acamprosate inhibits calcium influx through voltage-dependent calcium channels (al-Qatari and Littleton, 1995; Allgaier, Franke, Dobottka and Scheibler, 2000)
Acamprosate increases synaptic availability of the inhibitory neurotransmitter taurine (Dahchour, Quertemont and De Witte, 1996)
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Functional Significance of the Neuropharmacological Mechanism of
Action of Acamprosate
Functional Significance of the Neuropharmacological Mechanism of
Action of Acamprosate
Acamprosate acts as a partial co-agonist at the glutamate receptor through an allosteric interaction with the polyamine binding site on the NMDA glutamate receptor complex
Neuropharmacological consequences are to enhance activation of the glutamate receptor when levels of endogenous activators are low, but inhibit activation when levels of endogenous activators are high (such as during alcohol withdrawal)
Acamprosate acts as a partial co-agonist at the glutamate receptor through an allosteric interaction with the polyamine binding site on the NMDA glutamate receptor complex
Neuropharmacological consequences are to enhance activation of the glutamate receptor when levels of endogenous activators are low, but inhibit activation when levels of endogenous activators are high (such as during alcohol withdrawal)
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Neuroprotective Effects of Acamprosate
Neuroprotective Effects of Acamprosate
Acamprosate is neuroprotective against glutamate-induced neurotoxicity when enhanced by alcohol withdrawal in neocortical cultures of fetal rat brain (al Qatari, Khan, Harris and Littleton, 2001)
Acamprosate reduces excitatory postsynaptic field potentials in the hippocampus which may lead to protection against hyperexcitability such as epileptiform activity and seizures (Koob, Mason, De Witte, Littleton and Siggins, 2002)
Acamprosate decreases neurological deficits associated with cerebral ischemia in the rat (Engelhard, Werner, Lu, Mollenberg and Zieglgansberger, 2000)
Acamprosate decreases the severe mortality associated with alcohol withdrawal in the rat (Dahchour, Landron and De Witte, 2001)
Acamprosate normalizes sleep changes induced by alcohol and produces some cognitive-enhancing effects in healthy human volunteers (Koob, Mason, De Witte, Littleton and Siggins, 2002)
Acamprosate is neuroprotective against glutamate-induced neurotoxicity when enhanced by alcohol withdrawal in neocortical cultures of fetal rat brain (al Qatari, Khan, Harris and Littleton, 2001)
Acamprosate reduces excitatory postsynaptic field potentials in the hippocampus which may lead to protection against hyperexcitability such as epileptiform activity and seizures (Koob, Mason, De Witte, Littleton and Siggins, 2002)
Acamprosate decreases neurological deficits associated with cerebral ischemia in the rat (Engelhard, Werner, Lu, Mollenberg and Zieglgansberger, 2000)
Acamprosate decreases the severe mortality associated with alcohol withdrawal in the rat (Dahchour, Landron and De Witte, 2001)
Acamprosate normalizes sleep changes induced by alcohol and produces some cognitive-enhancing effects in healthy human volunteers (Koob, Mason, De Witte, Littleton and Siggins, 2002)
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Pre-Clinical and Clinical Pharmacokinetics of Acamprosate
Pre-Clinical and Clinical Pharmacokinetics of Acamprosate
Animal Human
Bioavailability 16% - rats 11%
Elimination Half-life 23-31 hours - rats 18 hours
Time to Steady State 5-7 days 5-7 daysPlasma Levels
Protein Binding None None
Elimination Not metabolized Not metabolizedRenal excretion Renal excretion
Lethality 6 grams/kg No known lethality
Animal Human
Bioavailability 16% - rats 11%
Elimination Half-life 23-31 hours - rats 18 hours
Time to Steady State 5-7 days 5-7 daysPlasma Levels
Protein Binding None None
Elimination Not metabolized Not metabolizedRenal excretion Renal excretion
Lethality 6 grams/kg No known lethality
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Drug Interactions with Acamprosate
Drug Interactions with Acamprosate
Animal Human
Alcohol None None
Disulfiram None None
Anticonvulsants None N/A
Anxiolytics None None
Antipsychotics None N/A
Antidepressants None None
Naltrexone N/A Plasma acamprosate
Animal Human
Alcohol None None
Disulfiram None None
Anticonvulsants None N/A
Anxiolytics None None
Antipsychotics None N/A
Antidepressants None None
Naltrexone N/A Plasma acamprosate
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ACAMPROSATEACAMPROSATEFrom: Spanagel R and Zieglgansberger W, Trends Pharmacol Sci, 1997, 18:54-59.
Schematic Neuron Showing the Possible Mode of Action of Acamprosate on
Alcohol-Related Effects
Schematic Neuron Showing the Possible Mode of Action of Acamprosate on
Alcohol-Related Effects