Galantamine: a cholinergic patch in the treatment of alcoholism: a randomized, placebo-controlled trial

The snowdrop, wellspring of galanthamine : A brief descriptive and scientific history

A history of the common snowdrop, Galanthus nivalis, is set out in folkloric fashion. Its religious connection is evident as well as the inspiration it arouses in artists and in ordinary persons. It is intended to shed light on the initial works relating to the snowdrop's alkaloid, galanthamine, performed by Soviet and Bulgarian scientists, which lie buried away and generally remain unknown. A brief history and nature of alkaloids continues with the emphasis placed on galanthamine. Heretofore hidden uses of snowdrops in traditional (folk) medicine are unveiled. An anticholinesterase with central and peripheral activity, feasible clinical indications with galanthamine are described. Certain disorders for which galanthamine has been deemed beneficial are presented for their historical value. Ongoing research regarding drugs and chemicals developed from the snowdrop and galanthamine is mentioned.

Brain Structure and Function in Recovery

Alcohol use disorder (AUD) commonly is associated with compromise in neurobiological and/or neurobehavioral processes. The severity of this compromise varies across individuals and outcomes, as does the degree to which recovery of function is achieved. This narrative review first summarizes neurobehavioral, neurophysiological, structural, and neurochemical aberrations/deficits that are frequently observed in people with AUD after detoxification. Subsequent sections review improvements across these domains during recovery, taking into account modulators of recovery to the extent permitted. Where appropriate, the discussion includes work integrating outcomes across domains, leveraging the strengths of diverse experimental methods. Interventions to ameliorate neurobiological or neurobehavioral deficits do not constitute a primary objective of this review. However, their consideration is a logical inclusion. Therefore, a limited introduction to existing methods is also presented.

Galantamine and Computerized Cognitive Behavioral Therapy for Cocaine Dependence: A Randomized Clinical Trial

OBJECTIVE

To examine whether galantamine, a cognitive-enhancing medication that is both acetylcholinesterase inhibitor and agonist at nicotinic acetylcholine receptors, is effective at improving cocaine use outcomes and cognitive functioning, alone and in combination with computerized cognitive behavioral therapy (CBT).

METHOD

A 12-week, randomized 2 × 2, factorial trial was conducted to evaluate galantamine versus placebo (double-blind) and computerized CBT plus standard methadone treatment versus standard methadone treatment alone in a community-based methadone maintenance program (September 2009-April 2015). One hundred twenty individuals diagnosed with DSM-IV cocaine use disorder were randomly assigned to the following conditions: (1) galantamine (8 mg/d) plus standard methadone maintenance treatment (treatment as usual [TAU]), (2) placebo plus TAU, (3) galantamine plus computerized CBT plus TAU, or (4) placebo plus computerized CBT plus TAU; medication administration was supervised at the time of daily methadone dosing. The primary cocaine use outcome was change in percent days of abstinence over time. Number of cocaine-negative urine toxicology screens submitted and cognitive function were secondary outcomes.

RESULTS

Random effect regression analysis indicated significant reductions in frequency of cocaine use over time, with significant treatment-by-time effects for both galantamine over placebo (F = 5.3, P = .02, d = 0.34) and computerized CBT over standard methadone treatment (F = 4.2, P = .04, d = 0.30) but no evidence of significant benefit of the combination over either treatment alone. Pretreatment to posttreatment comparisons of multiple indices of cognitive functioning, including sustained attention, indicated no benefit of galantamine over placebo.

CONCLUSIONS

Findings suggest benefits of galantamine and computerized CBT for reducing cocaine use in this sample. Although galantamine did not improve measures of cognitive function in this sample, multiple measures of cognitive function were associated with cocaine use outcomes, underlining the significance of cognitive function in cocaine treatment outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00809835.

Comparative biophysical characterization: A screening tool for acetylcholinesterase inhibitors

Among neurodegenerative diseases, Alzheimer’s disease (AD) is one of the most grievous disease. The oldest cholinergic hypothesis is used to elevate the level of cognitive impairment and acetylcholinesterase (AChE) comprises the major targeted enzyme in AD. Thus, acetylcholinesterase inhibitors (AChEI) constitutes the essential remedy for the treatment of AD. The study aims to evaluate the interactions between natural molecules and AChE by Surface Plasmon Resonance (SPR). The molecules like alkaloids, polyphenols and substrates of AChE have been considered for the study with a major emphasis on affinity and kinetics. To better understand the activity of small molecules, the investigation is supported by both experimental and theoretical approach such as fluorescence, Circular Dichroism (CD) and molecular docking studies. Amongst the screened ones tannic acid showed promising results compared with others. The methodology followed here have highlighted many molecules with a higher affinity towards AChE and these findings may take lead molecules generated in preclinical studies to treat neurodegenerative diseases. Additionally, we suggest a unique signature for the heterogeneous analyte model using competitive experiments for analyzing simultanous interactions of both the analytes.

The Cholinergic System as a Treatment Target for Opioid Use Disorder

Opioid overdoses recently became the leading cause of accidental death in the US, marking an increase in the severity of the opioid use disorder (OUD) epidemic that is impacting global health. Current treatment protocols for OUD are limited to opioid medications, including methadone, buprenorphine, and naltrexone. While these medications are effective in many cases, new treatments are required to more effectively address the rising societal and interpersonal costs associated with OUD. In this article, we review the opioid and cholinergic systems, and examine the potential of acetylcholine (ACh) as a treatment target for OUD. The cholinergic system includes enzymes that synthesize and degrade ACh and receptors that mediate the effects of ACh. ACh is involved in many central nervous system functions that are critical to the development and maintenance of OUD, such as reward and cognition. Medications that target the cholinergic system have been approved for the treatment of Alzheimer's disease, tobacco use disorder, and nausea. Clinical and preclinical studies suggest that medications such as cholinesterase inhibitors and scopolamine, which target components of the cholinergic system, show promise for the treatment of OUD and further investigations are warranted.

Effects of galantamine on smoking behavior and cognitive performance in treatment-seeking smokers prior to a quit attempt

OBJECTIVE

Drugs that enhance cholinergic transmission have demonstrated promise treating addictive disorders. Galantamine, an acetylcholinesterase inhibitor, may reduce cigarette smoking in otherwise healthy treatment-seeking smokers.

METHODS

The current study is a double-blind, placebo-controlled, study that randomized daily smokers (n = 60) to receive one of two doses of galantamine extended release (8 or 16 mg/day), or a placebo treatment. Participants completed a smoking choice task as well as study measures and cognitive tasks in the laboratory and daily life using ecological momentary assessment. Analysis focused on smoking behavior and satisfaction, cognitive performance, and decision to smoke prior to a quit attempt.

RESULTS

Linear mixed models demonstrated that, compared with placebo, both doses of galantamine reduced smoking in a laboratory choice task (p = 0.006) and decreased urine cotinine levels, but not self-reported cigarettes, during the pre-quit period (p = 0.007). Treatment had minimal effect on smoking satisfaction or cognitive performance.

CONCLUSIONS

The results suggest that galantamine reduces nicotine intake but it is unlikely that galantamine improves cognitive performance in otherwise healthy, treatment-seeking smokers. Larger randomized clinical trials can determine if galantamine adjunctive to addiction treatment can improve smoking treatment outcomes.

Advancing Pharmacotherapy Development from Preclinical Animal Studies

Animal models provide rapid, inexpensive assessments of an investigational drug's therapeutic potential. Ideally, they support the plausibility of therapeutic efficacy and provide a rationale for further investigation. Here, I discuss how the absence of clear effective-ineffective categories for alcohol use disorder (AUD) medications and biases in the clinical and preclinical literature affect the development of predictive preclinical alcohol dependence (AD) models. Invoking the analogical argument concept from the philosophy of science field, I discuss how models of excessive alcohol drinking support the plausibility of clinical pharmacotherapy effects. Even though these models are not likely be completely discriminative, they are sensitive to clinically effective medications and have revealed dozens of novel medication targets. In that context, I discuss recent preclinical work on GLP-1 receptor agonists, phosphodiesterase inhibitors, glucocorticoid receptor antagonists, nociception agonists and antagonists, and CRF1 antagonists. Clinically approved medications are available for each of these drug classes. I conclude by advocating a translational approach in which drugs are evaluated highly congruent preclinical models and human laboratory studies. Once translation is established, I suggest the burden is to develop hypothesis-based therapeutic interventions maximizing the impact of the confirmed pharmacotherapeutic effects in the context of additional variables falling outside the model.

Reduced Drinking in Alcohol Dependence Treatment, What Is the Evidence?

Abstinence from alcohol has been the prevailing treatment goal for individuals with alcohol dependence (AD) within the context of specialty alcohol treatment. Yet, alcohol use has been conceptualized as existing on a continuum. Importantly, most people who meet criteria for AD and could benefit from treatment never receive treatment. About half of these individuals do not seek treatment because they report a desire to continue drinking. To increase acceptability of treatment, reductions in alcohol consumption have been examined as alternative outcomes in treatment trials for AD. The current study reviews data which indicate that long-term reduction in alcohol consumption among patients with AD is possible. Controlled studies have tested reduced alcohol consumption and show sustained improvements in drinking reductions for many patients following behavioral treatments and pharmacotherapy. Evidence-based treatment guidelines and medicines development guidance authorities have taken note of these developments and accept "intermediate harm reduction" (European Medicines Agency) or "low-risk drinking limits" (US Federal Drug Administration) as optional trial endpoints. In conclusion, while abstinence remains the safest treatment goal for individuals with AD, evidence supports that reduced drinking approaches may be an important extension in the treatment of AD.

Acquisition and reinstatement of ethanol-induced conditioned place preference in rats: Effects of the cholinesterase inhibitors donepezil and rivastigmine

The present study examined the influence of the cholinesterase inhibitors donepezil (a selective inhibitor of acetylcholinesterase) and rivastigmine (also an inhibitor of butyrylcholinesterase) on the acquisition and reinstatement of ethanol-induced conditioned place preference (CPP) in rats. Before the CPP procedure, animals received a single injection of ethanol (0.5 g/kg, 10% w/v, intraperitoneally [i.p.]) for 15 days. The ethanol-induced CPP (biased method) was developed by four injections of ethanol (0.5 g/kg, 10% w/v, i.p.) every second day. Control rats received saline instead of ethanol. Donepezil (0.5, 1 or 3 mg/kg, i.p.) or rivastigmine (0.03, 0.5 or 1 mg/kg, i.p.) were administered before ethanol during conditioning or before the reinstatement of ethanol-induced CPP. The cholinesterase inhibitors were equally effective in increasing (dose dependently) the acquisition of ethanol-induced CPP. Furthermore, priming injections of both inhibitors reinstated (cross-reinstatement) the ethanol-induced CPP with similar efficacy. These effects of both cholinesterase inhibitors were reversed by mecamylamine (3 mg/kg, i.p.), a nicotinic acetylcholine receptor antagonist, but not by scopolamine (0.5 mg/kg, i.p.), a muscarinic acetylcholine receptor antagonist. Thus, our results show that the cholinergic system is involved in the reinforcing properties of ethanol, and nicotinic acetylcholine receptors play an important role in the relapse to ethanol-seeking behaviour.

A threshold model for opposing actions of acetylcholine on reward behavior: Molecular mechanisms and implications for treatment of substance abuse disorders

The cholinergic system plays important roles in both learning and addiction. Medications that modify cholinergic tone can have pronounced effects on behaviors reinforced by natural and drug reinforcers. Importantly, enhancing the action of acetylcholine (ACh) in the nucleus accumbens and ventral tegmental area (VTA) dopamine system can either augment or diminish these behaviors. A threshold model is presented that can explain these seemingly contradictory results. Relatively low levels of ACh rise above a lower threshold, facilitating behaviors supported by drugs or natural reinforcers. Further increases in cholinergic tone that rise above a second upper threshold oppose the same behaviors. Accordingly, cholinesterase inhibitors, or agonists for nicotinic or muscarinic receptors, each have the potential to produce biphasic effects on reward behaviors. Pretreatment with either nicotinic or muscarinic antagonists can block drug- or food- reinforced behavior by maintaining cholinergic tone below its lower threshold. Potential threshold mediators include desensitization of nicotinic receptors and biphasic effects of ACh on the firing of medium spiny neurons. Nicotinic receptors with high- and low- affinity appear to play greater roles in reward enhancement and inhibition, respectively. Cholinergic inhibition of natural and drug rewards may serve as mediators of previously described opponent processes. Future studies should evaluate cholinergic agents across a broader range of doses, and include a variety of reinforced behaviors.

The case of galantamine: repurposing and late blooming of a cholinergic drug

Galantamine is a reversible inhibitor of cholinesterases and an allosteric modulator of neuronal nicotinic acetylcholine receptors which restores reduced cholinergic tone in the central and peripheral nervous system. Characterized in the early 1950s in Bulgaria, it saw limited use for paralytic and neuropathic conditions until the cholinergic hypothesis of Alzheimer’s disease opened totally new perspectives for its utility. Although constricted supplies at extremely high prices and a fragmented patent situation made its repurposing challenging, galantamine was globally launched as an Alzheimer’s disease drug in 2000. Many other possible uses have been clinically investigated, and might yet develop into another drug career. This case study is presented as an example for classical on-target drug repurposing and the challenges that such a project can face.

Acetylcholine is a key neurotransmitter that regulates many functions in the CNS, as well as in other body organs, through the cholinergic system. Galantamine is a well-known alkaloid drug that modulates this system toward a higher cholinergic tone, and has been put to several therapeutic uses during the past decades, most recently, for Alzheimer’s disease. However, its known actions might allow repurposing toward even more applications not only in psychiatry and neurology but also in eye medicine and even in immunology. This article summarizes the claims, the evidence and the potential of galantamine beyond its currently approved uses.

Pharmacologic treatment of alcoholism

Progress in understanding the neuroscience of addiction has significantly advanced the development of more efficacious medications for the treatment of alcohol use disorders (AUD). While several medications have been approved by regulatory bodies around the world for the treatment of AUD, they are not universally efficacious. Recent research has yielded improved understanding of the genetics and brain circuits that underlie alcohol reward and its habitual use. This research has contributed to pharmacogenetic studies of medication response, and will ultimately lead to a more "personalized medicine" approach to AUD pharmacotherapy. This chapter summarizes work on clinically available medications (both approved by regulatory bodies and investigational) for the treatment of alcohol dependence, as well as the psychiatric disorders that are commonly comorbid with AUD. Studies that have evaluated genetic influences on medication response and those that have employed neuroimaging to probe mechanisms of medication action or response are highlighted. Finally, new targets discovered in animal models for possible pharmacologic intervention in humans are overviewed and future directions in medications development provided.

Emerging pharmacotherapies for alcohol dependence: a systematic review focusing on reduction in consumption

BACKGROUND

European Medicines Agency guidelines recognize two different treatment goals for alcohol dependence: abstinence and reduction in alcohol consumption. All currently approved agents are indicated for abstinence. This systematic review aimed to identify drugs in development for alcohol dependence treatment and to establish, based upon trial design, if any are seeking market authorization for reduction in consumption.

METHODS

We searched PubMed and Embase (December 2001-November 2011) to identify agents in development for alcohol dependence treatment. Additional studies were identified by searching ClinicalTrials.gov and the R&D Insight and Clinical Trials Insight databases. Studies in which the primary focus was treatment of comorbidity, or n≤20, were excluded. Studies were then classified as 'abstinence' if they: described a detoxification/alcohol withdrawal period; enrolled patients who had undergone detoxification previously; or presented relapse/abstinence rates as the primary outcome. Studies in patients actively drinking at baseline were classified as 'reduction in consumption'.

RESULTS

Of 602 abstracts identified, 45 full-text articles were eligible. Five monotherapies were in development for alcohol dependence treatment: topiramate, fluvoxamine, aripiprazole, flupenthixol and nalmefene. Nalmefene was the only agent whose sponsor was clearly seeking definitive approval for reduction in consumption. Development status was unclear for topiramate, fluvoxamine, aripiprazole and flupenthixol. Fifteen agents were examined in published exploratory investigator-initiated trials; the majority focused on abstinence. Ongoing (unpublished) trials tended to focus on reduction in consumption.

CONCLUSIONS

While published studies generally focused on abstinence, ongoing trials focused on reduction in consumption, suggesting a change in emphasis in the approach to treating alcohol dependence.

Acetylcholine, drug reward and substance use disorder treatment: intra- and interindividual striatal and accumbal neuron ensemble heterogeneity may explain apparent discrepant findings

Converging evidence from different independent laboratories suggests that acetylcholine may play an important role in drug reward and that modulation of the cholinergic system may be useful for the treatment of substance use disorders. In this commentary, we try to reconcile apparently discrepant animal behavioral, human behavioral and clinical data with a unifying hypothesis positing that the modulation of drug-versus natural stimuli-mediated reward by cholinergic interneurons in the nucleus accumbens (and the dorsal striatum) is restricted to distinct neuron ensembles that show considerable intra- and interindividual variation with respect to their spatial distribution. The precise targeting of these interindividually variable neuron ensembles would be a prerequisite for a successful pharmacotherapy based on the modulation of the cholinergic system. We also provide experimental data to support our unifying hypothesis.

Critical thoughts on current rodent models for evaluating potential treatments of alcohol addiction and withdrawal

Despite years of neurobiological research that have helped to identify potential therapeutic targets, we do not have a reliable pharmacological treatment for alcoholism. There are a range of possible explanations for this failure, including arguments that alcoholism is a spectrum disorder and that different population subtypes may respond to different treatments. This view is supported by categorisations such as early- and late-onset alcoholism, whilst multifactorial genetic factors may also alter responsivity to pharmacological agents. Furthermore, experience of alcohol withdrawal may play a role in future drinking in a way that may distinguish alcoholism from other forms of addiction. Additionally, our neurobiological models, based largely upon results from rodent studies, may not mimic specific aspects of the human condition and may reflect different underlying phenomena and biological processes from the clinical pattern. As a result, potential treatments may be targeting inappropriate aspects of alcohol-related behaviours. Instead, we suggest a more profitable approach is (a) to identify well-defined intermediate behavioural phenotypes in human experimental models that reflect defined aspects of the human clinical disorder and (b) to develop animal models that are homologous with those phenotypes in terms of psychological processes and underlying neurobiological mechanisms. This review describes an array of animal models currently used in the addiction field and what they tell us about alcoholism. We will then examine how established pharmacological agents have been developed using only a limited number of these models, before describing some alternative novel approaches to achieving homology between animal and human experimental measures.

Cognitive enhancers in the treatment of substance use disorders: clinical evidence

Attenuation of drug reward has been the major focus of medication development in the addiction area to date. With the growth of research in the area of cognitive neuroscience, the importance of executive function and inhibitory cognitive control in addictive disorders is becoming increasingly apparent. An emerging strategy in the pharmacotherapy of addictions and other psychiatric disorders involves the use of medications that improve cognitive function. In particular, agents that facilitate inhibitory and attentional control, improve abstraction, planning and mental flexibility could be beneficial in the treatment of substance use disorders. Because there are multiple neurotransmitter systems involved in the regulation of cognitive function, agents from a number of drug classes have been tested. In particular, agents acting through the cholinergic, adrenergic and glutamatergic systems have shown potential for improving cognitive function in a number of psychiatric and neurologic disorders, but most of these agents have not been tested in the treatment of individuals with substance use disorders. This manuscript provides a review of clinical data supporting the use of the major classes of cognitive enhancing agents in substance use disorders. Agents that have shown promise in cognitive enhancement in other disorders, and have a theoretical or mechanistic rationale for application to substance use disorders are also highlighted.

Pharmacological aspects of the acetylcholinesterase inhibitor galantamine

Several lines of evidence suggest that cholinergic deficits may contribute to the pathophysiology of psychiatric disorders as well as Alzheimer's disease. There is growing clinical evidence that galantamine, currently used for the treatment of Alzheimer's disease, may improve cognitive dysfunction and psychiatric illness in schizophrenia, major depression, bipolar disorder, and alcohol abuse. Since galantamine is a rather weak acetylcholinesterase inhibitor, but has additional allosteric potentiating effects at nicotinic receptors, it affects not only cholinergic transmission but also other neurotransmitter systems such as monoamines, glutamate, and γ-aminobutyric acid (GABA) through its allosteric mechanism. It is likely that these effects may result in more beneficial effects. To understand the underlying mechanism for the clinical effectiveness of galantamine, neuropharmacological studies have been performed in animal models of several psychiatric disorders. These studies suggest that not only the nicotinic receptor-modulating properties but also the muscarinic receptor activation contribute to the antipsychotic effect and improvement of cognitive dysfunction by galantamine. This review summaries the current status on the pharmacology of galantamine, focusing on its effect on neurotransmitter release and pharmacological studies in animal models of psychiatric disorders.

Addiction research centres and the nurturing of creativity department of addictive behaviour and addiction medicine, central institute of Mental Health, Mannheim, University of Heidelberg

Addictive behaviour is as prevalent in Germany as in other western countries, but in contrast to some European countries and the United States, very little money was given to this research field. Change came in the early 1990s, when the German government started to launch specific grants for addiction research. The first chair in addiction research was created in 1999 (Karl Mann) at the Central Institute of Mental Health Mannheim (CIMH; University of Heidelberg). The recruitment of a pre-clinical alcohol researcher as head of the department of psychopharmacology followed (Rainer Spanagel). This 'addiction research cluster' collaborates with several research groups at the CIMH (such as genetics). We inaugurated a clinical trial network which now comprises up to 20 treatment centres throughout Germany. Like most authors, we found effect sizes of different treatment modalities more in the low to moderate range, perhaps because of the heterogeneity of large patient samples. Therefore, we concentrated upon the biological basis of addiction in order to define more homogeneous 'subtypes' of patients for a better match with existing treatments. Results concerning genetics and neuroimaging (both animal and human) are promising, and could move our field towards a more personalized treatment approach. Our funding has been extended over the years, including involvement in several large European grants. We are studying substance-related problems as well as so-called 'behavioural addictions'. As a natural consequence of this development, we are deeply involved both in informing the general public on addiction issues as well as in counselling policy makers in Germany.

Alcoholism: A Systems Approach From Molecular Physiology to Addictive Behavior

Alcohol consumption is an integral part of daily life in many societies. The benefits associated with the production, sale, and use of alcoholic beverages come at an enormous cost to these societies. The World Health Organization ranks alcohol as one of the primary causes of the global burden of disease in industrialized countries. Alcohol-related diseases, especially alcoholism, are the result of cumulative responses to alcohol exposure, the genetic make-up of an individual, and the environmental perturbations over time. This complex gene × environment interaction, which has to be seen in a life-span perspective, leads to a large heterogeneity among alcohol-dependent patients, in terms of both the symptom dimensions and the severity of this disorder. Therefore, a reductionistic approach is not very practical if a better understanding of the pathological processes leading to an addictive behavior is to be achieved. Instead, a systems-oriented perspective in which the interactions and dynamics of all endogenous and environmental factors involved are centrally integrated, will lead to further progress in alcohol research. This review adheres to a systems biology perspective such that the interaction of alcohol with primary and secondary targets within the brain is described in relation to the behavioral consequences. As a result of the interaction of alcohol with these targets, alterations in gene expression and synaptic plasticity take place that lead to long-lasting alteration in neuronal network activity. As a subsequent consequence, alcohol-seeking responses ensue that can finally lead via complex environmental interactions to an addictive behavior.

Modifications of the Obsessive Compulsive Drinking Scale (OCDS-G) for use in longitudinal studies

Since the application of the Obsessive Compulsive Drinking Scale (OCDS) has been reported to be problematic when used to measure alcohol craving in longitudinal studies, we examined the following questions: (1) Is it possible to skip problematic quantity items? (2) Is the score calculation rule using the higher value of item pairs necessary? (3) Can the shortened version of the OCDS be applied alternatively? We examined two samples including a total of 355 alcohol-dependent patients: a multi center study sample (n=149) and a validation control sample (n=206). Neither an advantage of the score calculation rule nor the necessity of including items regarding alcohol consumption could be demonstrated. The exclusion of consumption items lead to a clear, stable 2-factor structure with a maximum stability (.81-.91). Retest-reliability ranged from r(tt)=.73 to r(tt)=.76 at an average time interval of 5 weeks. Concerning stability (.68-.81) and reliability (r(tt)=.76), the short version turned out to be equivalent. The short version of the OCDS seems to be sufficient. If different effects on cognitive and behavioral levels are expected, the 12-item version without the quantity items should be applied.

Neuropharmacology of alcohol addiction

Despite the generally held view that alcohol is an unspecific pharmacological agent, recent molecular pharmacology studies demonstrated that alcohol has only a few known primary targets. These are the NMDA, GABA(A), glycine, 5-hydroxytryptamine 3 (serotonin) and nicotinic ACh receptors as well as L-type Ca(2+) channels and G-protein-activated inwardly rectifying K(+) channels. Following this first hit of alcohol on specific targets in the brain, a second wave of indirect effects on a variety of neurotransmitter/neuropeptide systems is initiated that leads subsequently to the typical acute behavioural effects of alcohol, ranging from disinhibition to sedation and even hypnosis, with increasing concentrations of alcohol. Besides these acute pharmacodynamic aspects of alcohol, we discuss the neurochemical substrates that are involved in the initiation and maintenance phase of an alcohol drinking behaviour. Finally, addictive behaviour towards alcohol as measured by alcohol-seeking and relapse behaviour is reviewed in the context of specific neurotransmitter/neuropeptide systems and their signalling pathways. The activity of the mesolimbic dopaminergic system plays a crucial role during the initiation phase of alcohol consumption. Following long-term, chronic alcohol consumption virtually all brain neurotransmission seems to be affected, making it difficult to define which of the systems contributes the most to the transition from controlled to compulsive alcohol use. However, compulsive alcohol drinking is characterized by a decrease in the function of the reward neurocircuitry and a recruitment of antireward/stress mechanisms comes into place, with a hypertrophic corticotropin-releasing factor system and a hyperfunctional glutamatergic system being the most important ones.

Amaryllidaceae and Sceletium alkaloids

A great number of natural products, especially alkaloids, which exhibit a range of biological activities including acetylcholinesterase inhibition and antineoplastic, cardiovascular and immunostimulatory activities, have been isolated from the plants of the Amaryllidaceae family. this review summarizes isolation, biological activity, and synthetic studies of these alkaloids. The primary biosynthetic pathways of each type of alkaloids are also proposed.

The treatment of alcohol dependence

PURPOSE OF REVIEW

The present review summarizes current research on the management of alcohol dependence, including pharmacotherapy, psychosocial interventions and treatment of alcohol dependence with comorbid psychiatric disorders.

RECENT FINDINGS

Among recent studies, naltrexone has demonstrated the most consistent effect in reducing alcohol consumption in the context of behavioral therapy. In contrast to most previous studies, acamprosate did not show significant benefits on treatment outcomes relative to placebo. The combined use of naltrexone and acamprosate appeared to be safe and well tolerated but there was no additional therapeutic benefit. With the exception of topiramate, there are currently no new, effective medications for alcohol dependence. Of the psychosocial interventions, such as social behavior and network therapy, cognitive behavioral therapy, and motivational enhancement therapy, no one appears to be superior to another. Psychiatric comorbidity is common in alcohol-dependent patients; however, there are too few studies to effectively guide treatment practice.

SUMMARY

Progress has been made with pharmacotherapy and psychosocial interventions for alcohol-dependent individuals. More research is needed, however, in developing newer medications and psychosocial interventions in alcohol-dependent populations and in those with comorbid psychiatric conditions, and to improve the strategies to engage patients in continuing care.

Pharmakologische Rückfallprävention bei Alkohol- und Tabakabhängigkeit

A better understanding of the neurobiological substrates of alcohol and tobacco dependence has been accompanied by the increasing role of pharmacological relapse prevention. In alcohol dependence, substances which are able to block or ameliorate alcohol craving improve the maintenance of abstinence in combination with psychosocial treatment. In particular, the N-methyl-D-aspartate receptor antagonist acamprosate and the opiate receptor antagonist naltrexone have been shown to be effective in numerous trials. Administration starts immediately after detoxification and should last for 12 months. This treatment, however, is not a replacement for the psychosocial treatment of the alcohol dependence. Compared with placebo treatment, approximately twice as many patients remain abstinent under acamprosate 1 year after the end of treatment. The most widely studied and used pharmacotherapy for the treatment of tobacco dependence is nicotine containing medications. Nicotine replacement therapies (patch, gum, tablet, inhaler) have been shown to reduce tobacco craving and enhance abstinence. The only non-nicotine medication that has been approved in Germany is the antidepressant bupropion. Current studies identify particularly suitable subgroups of patients responding to more individualized pharmacological relapse prevention. A specific application of these substances will optimise the outcome for alcohol and tobacco dependent patients.