Dopaminergic and norepinephrinergic modulation of endogenous event-related potentials: A systematic review and meta-analysis

Event-related potentials (ERPs) represent the cortical processing of sensory, motor or cognitive functions invoked by particular events or stimuli. A current theory posits that the catecholaminergic neurotransmitters dopamine (DA) and norepinephrine (NE) modulate a number of endogenous ERPs during various cognitive processes. This manuscript aims to evaluate a leading neurotransmitter hypothesis with a systematic overview and meta-analysis of pharmacologic DA and NE manipulation of specific ERPs in healthy subjects during executive function. Specifically, the frontally-distributed P3a, N2, and Ne/ERN (or error-related negativity) are supposedly modulated primarily by DA, whereas the parietally-distributed P3b is thought to be modulated by NE. Based on preceding research, we refer to this distinction between frontally-distributed DA-sensitive and parietally-distributed NE-sensitive ERP components as the Extended Neurobiological Polich (ENP) hypothesis. Our systematic review and meta-analysis indicate that this distinction is too simplistic and many factors interact with DA and NE to influence these specific ERPs. These may include genetic factors, the specific cognitive processes engaged, or elements of study design, i.e. session or sequence effects or data-analysis strategies.

Bupropion Mediated Effects on Depression, Attention Deficit Hyperactivity Disorder, and Smoking Cessation

Bupropion had been in use since the late 1980s as an unconventional treatment for depression. Unlike other antidepressants, bupropion has no serotonergic activity and inhibits the reuptake of norepinephrine and dopamine. The drug has been used to treat depression, Attention Deficit Hyperactivity Disorder (ADHD), and smoking cessation. This investigation reviews the pharmacokinetic and pharmacodynamic effects of bupropion and its mechanisms of action and interactions with other drugs. We evaluated the efficacy of major on and off-label uses of bupropion, focusing on the indications, benefits, and adverse effects. Our review demonstrates that bupropion is superior to placebo and non-inferior to SSRIs such as escitalopram in treating major depressive disorder. More research is needed to determine positive patient-centered outcomes such as increases in quality of life. In the case of ADHD, the evidence for efficacy is mixed with poorly conducted randomized clinical trials, small sample sizes, and a lack of long-term assessments. The same is true in the case of bipolar disorder in which there is still limited and controversial data available on bupropion's safety and efficacy. In the case of smoking cessation, bupropion is found to be an effective anti-smoking drug with synergistic benefits when used as a combination therapy. We conclude that bupropion has the potential to provide benefit for a subset of patients who do not tolerate other typical antidepressants or anti-smoking therapies or for those whose treatment goals align with bupropion's unique side effect profile, such as smokers who wish to quit and lose weight. Additional research is needed to determine the drug's full clinical potential, particularly in the areas of adolescent depression and combination therapy with varenicline or dextromethorphan. Clinicians should use this review to understand the varied uses of the drug and identify the situations and patient populations in which bupropion can lend its greatest benefit.

Pharmacological Treatment of Generalised Anxiety Disorder: Current Practice and Future Directions

INTRODUCTION

Generalized Anxiety Disorder (GAD) is a common psychiatric condition, characterized by the presence of general apprehensiveness and excessive worry. Current management consists of a range of pharmacological and psychological treatments. However, many patients do not respond to first-line pharmacological treatments and novel anxiolytic drugs are being developed.

AREAS COVERED

In this review, the authors first discuss the diagnostic criteria and epidemiology of GAD. The effective pharmacological treatments for GAD and their tolerability are addressed. Current consensus guidelines for treatment of GAD are discussed, and maintenance treatment, the management of treatment resistance, and specific management of older adults and children/adolescents are considered. Finally, novel anxiolytics under development are discussed, with a focus on those which have entered clinical trials.

EXPERT OPINION

A range of effective treatments for GAD are available, particularly duloxetine, escitalopram, pregabalin, quetiapine, and venlafaxine. There is a limited evidence base to support the further pharmacological management of patients with GAD who have not responded to initial treatment. Although many novel anxiolytics have progressed to clinical trials, translation from animal models has been mostly unsuccessful. However, the potential of several compounds including certain psychedelics, ketamine, oxytocin, and agents modulating the orexin, endocannabinoid, and immune systems merits further study.

Depression roundtable: Is there a role for BoNT?

Depression can occur in the context of major depressive disorder or bipolar disorder. There are many effective and well-tolerated treatment options for most patients experiencing major depressive episodes, but for patients with treatment-resistant major depressive disorder or bipolar depression, current pharmacologic and non-pharmacologic options can be less efficacious, well tolerated, or accessible. Botulinum neurotoxin (BoNT) offers a novel approach to treating depression that is both safe and well-tolerated. Several potential mechanisms of action in depression are theorized, and studies support the efficacy of BoNT in major depression. Early data suggests that BoNT may be efficacious in bipolar depression and further study is warranted.

A comprehensive review and meta-analysis of neurological side effects related to second-generation antidepressants in individuals with major depressive disorder

Second-generation antidepressants (SGADs) often cause neurological side effects (SEs). This meta-analysis seeks to quantify the short-term rates of neurological SEs related to routinely used second-generation antidepressants used to treat major depressive disorder (MDD). A search of the PubMed, EMBASE,Cochrane Library databases and Web of Science was done to uncover double-blind, randomized, placebo-controlled studies evaluating the effectiveness of frequently used SGADs medicines in people with MDD. Qualifying studies were required to concentrate on the use of SGADs routinely used in MDD and to uncover data on treatment-emergent neurological SEs occurring within 12 weeks of therapy. Overall, 143 RCT studies containing 188 treatment arms were included in the meta-analyses. Most SGADs increased the risk of neurological SEs compared to placebo. The least tolerated antidepressants on the neurological tract were desvenlafaxine (OR=1.98; CI 0.85-4.65; p-value=0.12) and venlafaxine (OR=1.15; CI 0.96-1.38; p-value=0.13). Agomelatine, bupropion and vortioxetine exhibited reduced neurological SEs, showing diminished risk in insomnia (OR=0.56; CI 0.36-0.88; p-value=0.01), somnolence (OR=0.46; CI 0.27-0.79; p-value=0.01), vision blurred (OR=0.43; CI 0.19-0.96; p-value=0.04), respectively. Most SGADs did not or just marginally increased the risk of headache compared to placebo. In conclusion, frequently used SGADs demonstrated distinct patterns of neurological SEs, which physicians should consider when prescribing antidepressants to promote treatment adherence and favorable outcomes in patients with MDD.

Obesity and multiple myeloma: emerging mechanisms and perspectives

Obesity is a global pandemic that has been associated with the development of breast, endometrial, large intestine, renal, esophageal, and pancreatic cancer. Obesity is also involved in the development of cardiovascular disease and type 2 diabetes mellitus. Recently, an increase in the incidence of obesity-related cancers has been reported. Multiple myeloma (MM) is the second most common hematological malignancy, after lymphoma. The aim of this review is to examine the epidemiological data on obesity and MM, assess the effect of obesity on MM outcomes, evaluate the possible mechanisms through which obesity might increase the incidence of MM and provide the effects of obesity management on MM. Current evidence indicates that obesity may have an impact on the progression of monoclonal gammopathy of undetermined significance (MGUS) to MM and increase the prevalence of MM. However, data regarding the effect of obesity on MGUS incidence are controversial; further studies are needed to examine whether obesity affects the development of MGUS or the progression of MGUS to MM. In addition, obesity affects MM outcomes. Increased BMI is associated with decreased survival in patients with MM, while data regarding the effect of obesity on newly diagnosed MM subjects and autologous stem cell transplantation are limited. Interestingly, the obesity paradox may also apply to patients with relapsed/refractory MM who are overweight or obese, because they may have a survival advantage. The pathophysiological pathways linking obesity to MM are very complicated and include bone marrow adipose tissue; adipokines, such as adiponectin, leptin, resistin, and visfatin; inflammatory cytokines and growth factors, such as TNF-α and IL-6; hormones including insulin and the insulin-like growth factor system as well as sex hormones. In terms of the effect of pharmacological management of obesity, orlistat has been shown to alter the proliferation of MM cells, whereas no data exist on glucagon-like peptide-1 receptor agonists, naltrexone/bupropion, or phentermine/topiramate. Bariatric surgery may be associated with a reduction in the incidence of MM, however, further studies are needed.

Effects of bupropion on sign- and goal-tracking in male Sprague Dawley rats

Relapse into addiction is often triggered by cues that have a Pavlovian association with drugs and drug-taking. Sign-tracking involves approach of and interaction with Pavlovian conditioned signals for appetitive events (as opposed to goal-tracking, which involves approach of the site of the appetitive events themselves) and may be important in understanding cue-driven relapse. Bupropion is an atypical antidepressant and smoking cessation aid with effects on dopamine and norepinephrine that may have some utility in reducing sign-tracking. Male Sprague-Dawley rats were trained in a task where sign- and goal-tracking were possible and then administered doses of bupropion during a test phase. Bupropion decreased measures of sign-tracking and increased goal-tracking. This suggests that bupropion might be a useful adjunct medication for many kinds of behavioral disorders in which cue-driven behavior is problematic.

The Impact of Various Methods of Obesity Treatment on the Quality of Life and Mental Health-A Narrative Review

Obesity, defined as body mass index (BMI) ≥ 30 kg/m², is one of the most important public health problems. Over one billion people are obese, including 650 million adults, which is 13% of the worldwide population, according to the World Health Organization (WHO). Similar to obesity, mental disorders such as depression and anxiety are huge social problems with serious health implications. There are numerous studies proving a strong link between the prevalence of obesity and depressive disorders, and being overweight is also associated with decreased health-related quality of life (HRQoL). Due to the broad negative impact of obesity on a patient's health, proper treatment is crucial. Currently, the literature describes many methods of treatment such as dietary treatment, pharmacotherapy using glucagon-like peptide-1 (GLP-1) analogs, orlistat, naltrexone/bupropion (NB), or finally bariatric surgery. The most commonly used methods of obesity treatment significantly improve the patient's quality of life and reduce the symptoms of depression and anxiety. The aim of our study was to summarize the knowledge about the impact of known and commonly used methods of obesity treatment (e.g., dietary treatment, bariatric surgery, and pharmacological treatment) on mental health and quality of life. For this purpose, we will try to review the current scientific data, originating from international reports.

Nitrogen-centered radical-mediated α-sulfonimidation of ketones

A nitrogen-centered radical mediated α-sulfonimidation of carbonyl compounds that was initiated by a benzenesulfonimide radical generated from NFSI under the catalytic reduction of TEMPO is established.

Polypharmacy composition and patient- and provider-related variation in patients with epilepsy

OBJECTIVE

To describe polypharmacy composition, and the degree to which patients versus providers contribute to variation in medication fills, in people with epilepsy.

METHODS

We performed a retrospective study of Medicare beneficiaries with epilepsy (antiseizure medication plus diagnostic codes) in 2014 (N = 78,048). We described total number of medications and prescribers, and specific medications. Multilevel models evaluated the percentage of variation in two outcomes (1. number of medications per patient-provider dyad, and 2. whether a medication was filled within thirty days of a visit) due to patient-to-patient differences versus provider-to-provider differences.

RESULTS

Patients filled a median of 12 (interquartile range [IQR] 8-17) medications, from median of 5 (IQR 3-7) prescribers. Twenty-two percent filled an opioid, and 61% filled at least three central nervous system medications. Levetiracetam was the most common medication (40%), followed by hydrocodone/acetaminophen (27%). The strongest predictor of medications per patient was Charlson comorbidity index (7.5 [95% confidence interval (CI) 7.2-7.8] additional medications for index 8+ versus 0). Provider-to-provider variation explained 36% of variation in number of medications per patient, whereas patient-to-patient variation explained only 2% of variation. Provider-to-provider variation explained 57% of variation in whether a patient filled a medication within 30 days of a visit, whereas patient-to-patient variation explained only 30% of variation.

CONCLUSION

Patients with epilepsy fill a large number of medications from a large number of providers, including high-risk medications. Variation in medication fills was substantially more related to provider-to-provider rather than patient-to-patient variation. The better understanding of drivers of high-prescribing practices may reduce avoidable medication-related harms.

Bupropion-Associated Delayed Onset Urticaria

Bupropion is an oral antidepressant that is commonly used to treat various mood disorders. Its therapeutic mechanism of action results from inhibiting the reuptake of norepinephrine and dopamine. Bupropion is generally well-tolerated and patients usually experience no side effects or mild adverse events. Rarely, hypersensitivity reactions to bupropion, such as urticaria, have been observed. However, the prevalence of delayed onset bupropion-associated urticaria may not be properly reflected in the literature due to misdiagnosis of the condition caused by its atypical presentation. We report a 20-year-old man with delayed onset bupropion-associated urticaria; he had been on bupropion for three weeks and subsequently developed new severely pruritic, erythematous wheals on his abdomen, bilateral flanks, and upper extremities. The clinical features of this rare adverse reaction to bupropion are also summarized.

Probing the Release of Bupropion and Naltrexone Hydrochloride Salts from Biopolymeric Matrices of Diverse Chemical Structures

In the last decades, the notion of including excipients in the formulations, as inert substances aiding production processes, has changed and they are recently viewed as multifunctional discrete entities. It is now well documented that excipients serve several roles, spreading from the stabilization and modified release, to providing biocompatible properties and targeting moieties. The aim of this study was to develop matrix-based oral drug delivery systems of bupropion hydrochloride (BUP·HCl) and naltrexone hydrochloride (NTX·HCl), suitable for releasing these active substances in a modified manner, providing a stable level of drug release, which is simultaneously therapeutically effective and non-toxic, thus reducing side effects, after a single dose administration, throughout the gastrointestinal tract. The new formulations, employing hydroxypropylmethycellulose (HPMC K15M) (a cellulosic polymer, which, generally hydrates to form a gelatinous layer that is critical to prevent wetting and rapid drug release from the matrices), poly(methacylic acid-co-ethyl acrylate) 1:1 (Eudragit^® L100-55: effective for site specific drug delivery in intestine), poly(ethylene oxide) (PEO) (7 × 10⁶: a high molecular weight polymer, water-soluble, in micro-granular powder form), as the rate controlling polymers, were chosen to lead to a "soothing out" release pattern of these drugs, at 0 ≤ t ≤ 120 min. Moreover, the release of the two drugs from the ulvan-based tablets, was found to follow the desired profile, throughout the entire course of the dissolution experiments.

Bupropion increases cerebral activation in auditory affective processing: A randomized controlled fMRI study

INTRODUCTION

Bupropion is an antidepressant with less possibility to give rise to emotional blunting as side effect, and it also acts on improving negative self-recognition in a depressive state. Previous neuroimaging studies indicated a change in brain function by facial expression as an effect of antidepressants. As well as facial expression, vocal affective processing is essential for accurately recognizing another's feelings, but to our knowledge, no study has investigated whether bupropion affects the cerebral function of recognition of auditory affective processing. In this study, we aimed to investigate the acute effect of bupropion on cerebral response to vocal affective processing.

METHODS

Sixteen healthy volunteers (male = 8) participated in this study. With a randomized placebo-controlled within-subject trial, two series of fMRI scans, using either placebo or bupropion (150 mg), were examined. An auditory emotional valence judgement task was performed during fMRI scanning. The acute effects of bupropion on cerebral activation in the emotional circuit and behavioral performance during emotional processing were analyzed.

RESULTS

Compared with placebo, bupropion caused a significantly greater activation of emotional voices in the left insula and right superior temporal gyrus, whereas the amygdala was not activated. By bupropion, a significantly greater activation of the positive emotional circuit was observed at the superior temporal gyrus and middle frontal gyrus. As for behavioral performance, no significant difference was observed between placebo and bupropion.

CONCLUSIONS

Our findings suggest that bupropion enhances the cerebral response to affective processing, especially positive emotional vocalizations, indicating a possible mechanism underlying the therapeutic effects for patients with depression.

Polypharmacy in patients with epilepsy: A nationally representative cross-sectional study

OBJECTIVE

The objective of the study was to characterize the prevalence of polypharmacy and central nervous system (CNS)-acting medications in patients with epilepsy, and particular types of medications.

METHODS

This was a retrospective cross-sectional study using data from the nationally representative National Health and Nutrition Examination Survey (NHANES). We included patients who reported taking at least one prescription medication in order to treat seizures or epilepsy during NHANES survey years 2013-2016. We assessed the number and types of drugs and predictors of total number of medications using a negative binomial regression. We then assessed prevalence of polypharmacy (≥5 medications), CNS polypharmacy (≥3 CNS-acting medications) and additional CNS-acting medications, and drugs that lower the seizure threshold (i.e., bupropion and tramadol), and extrapolated prevalence to estimated affected US population.

RESULTS

The NHANES contained 20,146 participants, of whom 135 reported taking ≥1 antiseizure medication (ASM) for seizures or epilepsy representing 2,399,520 US citizens using NHANES's sampling frame. Patients reported taking a mean 5.3 (95% confidence interval (CI): 4.3-6.3) prescription medications. Adjusting for race, sex, and uninsurance, both age and number of chronic conditions predicted increased number of medications (incident rate ratio (IRR) per decade: 1.16, 95% CI: 1.04-1.28; IRR per chronic condition: 1.19, 95% CI: 1.11-1.27). Polypharmacy was reported by 47% (95% CI: 38%-57%) of patients, CNS polypharmacy by 34% (23%-47%), benzodiazepine use by 21% (14%-30%), opioid use by 16% (11%-24%), benzodiazepine plus opioid use by 6% (3%-14%), and 6% (2%-15%) reported a drug that lowers the seizure threshold. Twelve percent (7%-20%) took an opioid with either a benzodiazepine or gabapentinoid.

CONCLUSIONS

Polypharmacy is common in patients with epilepsy. Patients taking ASMs frequently reported also taking other CNS-acting medications (i.e., opioids, benzodiazepines, seizure threshold-lowering medications), and medication combinations with black box warnings. Central nervous system polypharmacy poses health risks. Future research is needed to explore drivers of polypharmacy and strategies to help mitigate potentially harmful prescription use in this high-risk population.

Stereoselective Bupropion Hydroxylation by Cytochrome P450 CYP2B6 and Cytochrome P450 Oxidoreductase Genetic Variants

Bioactivation of the antidepressant and smoking cessation drug bupropion is catalyzed predominantly by CYP2B6. The metabolite hydroxybupropion derived from t-butylhydroxylation is considered to contribute to the antidepressant and smoking-cessation effects of the parent drug. Bupropion hydroxylation is the canonical in vitro and in vivo probe for CYP2B6 activity. P450 also requires obligate partnership with P450 oxidoreductase (POR). Human CYP2B6 and POR genes are highly polymorphic. Some CYP2B6 variants affect bupropion disposition. This investigation evaluated the influence of several human CYP2B6 and POR genetic variants on stereoselective bupropion metabolism, using an insect cell coexpression system containing CYP2B6, POR, and cytochrome b ₅ Based on intrinsic clearances (Cl_ints), relative activities for S,S-hydroxybupropion formation were in the order CYP2B6.4 > CYP2B6.1 > CYP2B6.17 > CYP2B6.5 > CYP2B6.6 ≈ CYP2B6.26 ≈ CYP2B6.19 > CYP2B6.7 > CYP2B6.9 > > CYP2B6.16 and CYP2B6.18; relative activities for R,R-hydroxybupropion formation were in the order CYP2B6.17 > CYP2B6.4 > CYP2B6.1 > CYP2B6.5 ≈ CYP2B6.19 ≈ CYP2B6.26 > CYP2B6.6 > CYP2B6.7 ≈ CYP2B6.9 > > CYP2B6.16 and CYP2B6.18. Bupropion hydroxylation was not influenced by POR variants. CYP2B6-catalyzed bupropion hydroxylation is stereoselective. Though V_max and K_m varied widely among CYP2B6 variants, stereoselectivity was preserved, reflected by similar Cl_int(S,S-hydroxybupropion)/Cl_int(R,R-hydroxybupropion) ratios (1.8-2.9), except CYP2B6.17, which was less enantioselective. Established concordance between human bupropion hydroxylation in vitro and in vivo, together with these new results, suggests additional CYP2B6 variants may influence human bupropion disposition. SIGNIFICANCE STATEMENT: Bupropion pharmacokinetics, metabolism, and clinical effects are affected by the CYP2B6*6 polymorphism. Other expressed CYP2B6 polymorphisms had diminished (*5, *6, *7, *9, *19, *26) or defective (*16, *18) in vitro bupropion hydroxylation. P450 oxidoreductase genetic variants had no effect on metabolism, suggesting no clinical consequence of this polymorphism. These CYP2B6 polymorphisms may portend diminished in vivo bupropion hydroxylation and predict additional clinically important variant alleles.

Bupropion increases activation in nucleus accumbens during anticipation of monetary reward

RATIONALE

Bupropion is used for major depressive disorder, smoking cessation aid, and obesity. It blocks reuptake of dopamine and noradrenaline and antagonizes nicotinic acetylcholine receptor. Animal studies showed that bupropion enhanced rewarding effects. In addition, bupropion has the potential to treat patients with reward processing dysfunction. However, neural substrates underlying the bupropion effects on reward function in human subjects are not fully understood.

OBJECTIVES

We investigated single-dose administration of bupropion on neural response of reward anticipation in healthy subjects using a monetary incentive delay (MID) task by functional magnetic resonance imaging (fMRI), especially focusing on nucleus accumbens (NAc) activity to non-drug reward stimuli under bupropion treatment.

METHODS

We used a randomized placebo-controlled within-subject crossover design. Fifteen healthy adults participated in two series of an fMRI study, taking either placebo or bupropion. The participants performed the MID task during the fMRI scanning. The effects of bupropion on behavioral performance and blood oxygenation level-dependent (BOLD) signal in NAc during anticipation of monetary gain were analyzed.

RESULTS

We found that bupropion significantly increased BOLD responses in NAc during monetary reward anticipation. The increased BOLD responses in NAc were observed with both low and high reward incentive cues. There was no significant difference between placebo and bupropion in behavioral performance.

CONCLUSIONS

Our findings provide support for the notion that bupropion enhances non-drug rewarding effects, suggesting a possible mechanism underlying therapeutic effects for patients with motivational deficit.

Common Polymorphisms of CYP2B6 Influence Stereoselective Bupropion Disposition

Bupropion hydroxylation is a bioactivation and metabolic pathway, and the standard clinical CYP2B6 probe. This investigation determined the influence of CYP2B6 allelic variants on clinical concentrations and metabolism of bupropion enantiomers. Secondary objectives evaluated the influence of CYP2C19 and P450 oxidoreductase variants. Healthy volunteers in specific cohorts (CYP2B6*1/*1, CYP2B6*1/*6, CYP2B6*6/*6, and also CYP2B6*4 carriers) received single-dose oral bupropion. Plasma and urine bupropion and hydroxybupropion was quantified. Subjects were also genotyped for CYP2C19 and P450 oxidoreductase variants. Hydroxylation of both bupropion enantiomers, assessed by plasma hydroxybupropion/bupropion AUC ratios and urine hydroxybupropion formation clearances, was lower in CYP2B6*6/*6 but not CYP2B6*1/*6 compared with CYP2B6*1/*1 genotypes, and numerically greater in CYP2B6*4 carriers. CYP2C19 and P450 oxidoreductase variants did not influence bupropion enantiomers hydroxylation or plasma concentrations. The results show that clinical hydroxylation of both bupropion enantiomers was equivalently influenced by CYP2B6 allelic variation. CYP2B6 polymorphisms affect S-bupropion bioactivation, which may affect therapeutic outcomes.

Neuropharmacology of Synthetic Cathinones

Synthetic cathinones are derivatives of the naturally occurring compound cathinone, the main psychoactive ingredient in the khat plant Catha edulis. Cathinone is the β-keto analog of amphetamine, and all synthetic cathinones display a β-keto moiety in their structure. Several synthetic cathinones are widely prescribed medications (e.g., bupropion, Wellbutrin^®), while others are problematic drugs of abuse (e.g., 4-methylmethcathinone, mephedrone). Similar to amphetamines, synthetic cathinones are psychomotor stimulants that exert their effects by impairing the normal function of plasma membrane transporters for dopamine (DAT), norepinephrine (NET), and 5-HT (SERT). Ring-substituted cathinones like mephedrone are transporter substrates that evoke neurotransmitter release by reversing the normal direction of transporter flux (i.e., releasers), whereas pyrrolidine-containing cathinones like 3,4-methylenedioxypyrovalerone (MDPV) are potent transporter inhibitors that block neurotransmitter uptake (i.e., blockers). Regardless of molecular mechanism, all synthetic cathinones increase extracellular monoamine concentrations in the brain, thereby enhancing cell-to-cell monoamine signaling. Here, we briefly review the mechanisms of action, structure-activity relationships, and in vivo pharmacology of synthetic cathinones. Overall, the findings show that certain synthetic cathinones are powerful drugs of abuse that could pose significant risk to users.

Bupropion for attention deficit hyperactivity disorder (ADHD) in adults

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurobiological condition, characterised by behavioral and cognitive symptoms such as inattention, impulsivity and/or excessive activity. The syndrome is commonly accompanied by psychiatric comorbidities and is associated with educational and occupational underachievement.Although psychostimulant medications are the mainstay of treatment for ADHD, not all adults respond optimally to, or can tolerate, these medicines. Thus, alternative non-stimulant treatment approaches for ADHD have been explored. One of these alternatives is bupropion, an aminoketone antidepressant and non-competitive antagonism of nicotinic acetylcholine receptors. Bupropion is registered for the treatment of depression and smoking cessation, but is also used off-label to treat ADHD.

OBJECTIVES

To assess the effects and safety of bupropion for the treatment of adults with ADHD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and seven other databases in February 2017. We also searched three trials registers and three online theses portals. In addition, we checked references of included studies and contacted study authors to identify potentially relevant studies that were missed by our search.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that evaluated the effects (including adverse effects) of bupropion compared to placebo in adults with ADHD.

DATA COLLECTION AND ANALYSIS

Two review authors (WV, GB) independently screened records and extracted data using a data extraction sheet that we tested in a pilot study. We extracted all relevant data on study characteristics and results. We assessed risks of bias using the Cochrane 'Risk of bias' tool, and assessed the overall quality of evidence using the GRADE approach. We used a fixed-effect model to pool the results across studies.

MAIN RESULTS

We included six studies with a total of 438 participants. Five studies were conducted in the USA, and one in Iran. All studies evaluated a long-acting version of bupropion, with the dosage ranging from 150 mg up to 450 mg daily. Study intervention length varied from six to 10 weeks. Four studies explicitly excluded participants with psychiatric comorbidity and one study included only participants with opioid dependency. Four studies were funded by industry, but the impact of this on study results is unknown. Two studies were publicly funded and in one of these studies, the lead author was a consultant for several pharmaceutical companies and also received investigator-driven funding from two companies, however none of these companies manufacture bupropion. We judged none of the studies to be free of bias because for most risk of bias domains the study reports failed to provide sufficient details. Using the GRADE approach, we rated the overall quality of evidence as low. We downgraded the quality of the evidence because of serious risk of bias and serious imprecision due to small sample sizes.We found low-quality evidence that bupropion decreased the severity of ADHD symptoms (standardised mean difference -0.50, 95% confidence interval (CI) -0.86 to -0.15, 3 studies, 129 participants), and increased the proportion of participants achieving clinical improvement (risk ratio (RR) 1.50, 95% CI 1.13 to 1.99, 4 studies, 315 participants), and reporting an improvement on the Clinical Global Impression - Improvement scale (RR 1.78, 95% CI 1.27 to 2.50, 5 studies, 337 participants). There was low-quality evidence that the proportion of participants who withdrew due to any adverse effect was similar in the bupropion and placebo groups (RR 1.20, 95% CI 0.35 to 4.10, 3 studies, 253 participants). The results were very similar when using a random-effects model and when we analysed only studies that excluded participants with a psychiatric comorbidity.

AUTHORS' CONCLUSIONS

The findings of this review, which compared bupropion to placebo for adult ADHD, indicate a possible benefit of bupropion. We found low-quality evidence that bupropion decreased the severity of ADHD symptoms and moderately increased the proportion of participants achieving a significant clinical improvement in ADHD symptoms. Furthermore, we found low-quality evidence that the tolerability of bupropion is similar to that of placebo. In the pharmacological treatment of adults with ADHD, extended- or sustained-release bupropion may be an alternative to stimulants. The low-quality evidence indicates uncertainty with respect to the pooled effect estimates. Further research is very likely to change these estimates. More research is needed to reach more definite conclusions as well as clarifying the optimal target population for this medicine. Treatment response remains to be reported in a DSM5-diagnosed population. There is also a lack of knowledge on long-term outcomes.

Concurrent Electroconvulsive Therapy and Bupropion Treatment

BACKGROUND

Bupropion is associated with a dose-dependent increased risk of seizures. Use of concomitant bupropion and electroconvulsive therapy (ECT) remains controversial because of an increased risk of prolonged seizures. This is the first systematic evaluation of the effect of bupropion on ECT.

METHODS

A case group (n = 119), patients treated with concomitant ECT and bupropion, was compared with an age and gender frequency-matched control group (n = 261), treated with only ECT. Electroconvulsive therapy treatment data including seizure length, number of treatments, and concurrent medications were extracted. Longitudinal mixed models examined ECT versus ECT + bupropion group differences over the course of treatments measured by seizure duration (electroencephalogram [EEG] and motor). Multivariable models examined the total number of treatments and first and last seizure duration. All models considered group differences with ECT treatment measures adjusted for age, gender, benzodiazepine treatment, lead placement, and setting.

RESULTS

Electroconvulsive therapy treatment with bupropion led to shorter motor seizure duration (0.047) and EEG seizure duration (P = 0.001). The number of ECT treatments (7.3 vs 7.0 treatments; P = 0.23), respectively, or the probability of a prolonged seizure (P = 0.15) was not significantly different. Benzodiazepine use was significantly more common in control subjects (P = 0.01).

LIMITATIONS

This is a retrospective analysis limited in part by unavailable variables (seizure threshold, nature of EEG and motor seizure monitoring, type of ECT device, dosing and formulation of bupropion, and duration of the current depressive illness).

CONCLUSIONS

This study revealed a significantly shorter duration in seizure length with ECT + concomitant bupropion, but not in the number of required treatments in those treated compared with ECT without bupropion. There remains a critical need to reevaluate the efficacy of concomitant use of psychotropic medications + ECT.

Making the Case for 'Power Abuse Disorder' as a Nosologic Entity

The development of societies and cultures arguably is based on the ability of human primates to form hierarchies in which some individuals acquire and wield power, that is, control resources and influence and control the behavior of their conspecifics. In the following, we focus on the type of human primate power wielding that (a) harms and (b) produces excessive negative emotions in (1) the victim(s) of the power wielder and (2) the power wielder her/himself. If such a harmful behavior of the power wielder is not accompanied by an ethically justifiable benefit for the involved human primate groups, it can be considered "power abuse." We propose to term the associated behaviors, cognitions, and emotions of the power wielder as "power abuse disorder" (PAD). This behavior results from what we consider addictive behavior of the power abuse disordered (PADed) power wielder. PAD can be diagnosed on the basis of the World Health Organization's criteria for "dependence syndrome" as listed in the International Classification of Diseases version 10. We will demonstrate that many PADed individuals may very likely carry the Zeitgeist diagnosis "burnout." This article reviews the current understanding of the neural correlates of PAD and suggests future research. Based on the available evidence, PAD seems to be associated with a dysfunction of the mesocorticolimbic dopamine system, rendering PADed individuals vulnerable for psychostimulant abuse/dependence, and suggesting specific pharmacotherapeutic approaches to treat PAD.

Method-of-use study of naltrexone sustained release (SR)/bupropion SR on body weight in individuals with obesity

OBJECTIVE

This study assessed the effects of 32 mg naltrexone sustained release (SR)/360 mg bupropion SR (NB) on body weight in adults with obesity, with comprehensive lifestyle intervention (CLI), for 78 weeks.

METHODS

In this phase 3b, randomized, open-label, controlled study, subjects received NB + CLI or usual care (standard diet/exercise advice) for 26 weeks. NB subjects not achieving 5% weight loss at week 16 were discontinued, as indicated by product labeling. After week 26, usual care subjects began NB + CLI. Assessments continued through week 78. The primary end point was percent change in weight from baseline to week 26 in the per protocol population. Other end points included percentage of subjects achieving ≥5%, ≥10%, and ≥15% weight loss, percent change in weight at week 78, and adverse events (AEs) necessitating study medication discontinuation.

RESULTS

NB + CLI subjects lost significantly more weight than usual care subjects at week 26 (8.52% difference; P < 0.0001). Weight loss persisted through 78 weeks. In total, 20.7% of subjects discontinued medication for AEs, including 7.0% for nausea.

CONCLUSIONS

Treatment with NB, used as indicated by prescribing information and with CLI, significantly improved weight loss over usual care alone. NB-facilitated weight loss was sustained for 78 weeks and was deemed safe and well tolerated.

Effects of bupropion sustained release on task-related EEG alpha activity in smokers: Individual differences in drug response

The mechanisms underlying bupropion's efficacy as an antidepressant and a smoking cessation aid are far from being fully characterized. The present study is the first to examine the effects of bupropion on visuospatial task-related parietal EEG alpha power asymmetry-an asymmetry that has previously been found to be associated with severity of depressive symptoms (i.e., the more depressive symptoms, the greater alpha power in the right vs. left parietal area [Henriques & Davidson, 1997; Rabe, Debener, Brocke, & Beauducel, 2005]). Participants, all of whom were smokers and none of whom were clinically depressed, were randomly assigned to the Placebo group (n = 79) or Bupropion group (n = 31) in a double-blind study. EEG during the performance of the visuospatial task was collected before and after 14 days on placebo or bupropion sustained-release capsules. Relative to the Placebo group, the Bupropion group (especially, the Bupropion subgroup who had a positive right versus left parietal alpha power asymmetry at pretreatment) had a reduction in the parietal alpha asymmetry (driven largely by a decrease in right parietal alpha power). These findings support the hypothesis that bupropion can induce changes in parietal EEG asymmetry that have been shown in previous literature to be associated with a reduction in depressive states and traits. (PsycINFO Database Record

Sexual Dysfunction Due to Psychotropic Medications

Sexual functioning is important to assess in patients with psychiatric illness as both the condition and associated treatment may contribute to sexual dysfunction (SD). Antidepressant medications, mood stabilizers, antipsychotics, and antianxiety agents may be associated with SD related to drug mechanism of action. Sexual adverse effects may be related to genetic risk factors, impact on neurotransmitters and hormones, and psychological elements. Effective strategies to manage medication-induced sexual dysfunction are initial choice of a drug unlikely to cause SD, switching to a different medication, and adding an antidote to reverse SD. Appropriate interventions should be determined on a clinical case-by-case basis.

Chiral Plasma Pharmacokinetics and Urinary Excretion of Bupropion and Metabolites in Healthy Volunteers

Bupropion, widely used as an antidepressant and smoking cessation aid, undergoes complex metabolism to yield numerous metabolites with unique disposition, effect, and drug-drug interactions (DDIs) in humans. The stereoselective plasma and urinary pharmacokinetics of bupropion and its metabolites were evaluated to understand their potential contributions to bupropion effects. Healthy human volunteers (n = 15) were administered a single oral dose of racemic bupropion (100 mg), which was followed by collection of plasma and urine samples and determination of bupropion and metabolite concentrations using novel liquid chromatography-tandem mass spectrometry assays. Time-dependent, elimination rate-limited, stereoselective pharmacokinetics were observed for all bupropion metabolites. Area under the plasma concentration-time curve from zero to infinity ratios were on average approximately 65, 6, 6, and 4 and Cmax ratios were approximately 35, 6, 3, and 0.5 for (2R,3R)-/(2S,3S)-hydroxybupropion, R-/S-bupropion, (1S,2R)-/(1R,2S)-erythrohydrobupropion, and (1R,2R)-/(1S,2S)-threohydrobupropion, respectively. The R-/S-bupropion and (1R,2R)-/(1S,2S)-threohydrobupropion ratios are likely indicative of higher presystemic metabolism of S- versus R-bupropion by carbonyl reductases. Interestingly, the apparent renal clearance of (2S,3S)-hydroxybupropion was almost 10-fold higher than that of (2R,3R)-hydroxybupropion. The prediction of steady-state pharmacokinetics demonstrated differential stereospecific accumulation [partial area under the plasma concentration-time curve after the final simulated bupropion dose (300-312 hours) from 185 to 37,447 nM⋅h] and elimination [terminal half-life of approximately 7-46 hours] of bupropion metabolites, which may explain observed stereoselective differences in bupropion effect and DDI risk with CYP2D6 at steady state. Further elucidation of bupropion and metabolite disposition suggests that bupropion is not a reliable in vivo marker of CYP2B6 activity. In summary, to our knowledge, this is the first comprehensive report to provide novel insight into mechanisms underlying bupropion disposition by detailing the stereoselective pharmacokinetics of individual bupropion metabolites, which will enhance clinical understanding of bupropion's effects and DDIs with CYP2D6.

Development and validation of a high-throughput stereoselective LC-MS/MS assay for bupropion, hydroxybupropion, erythrohydrobupropion, and threohydrobupropion in human plasma

A stereoselective analytical method was developed and validated for the quantification of bupropion, and principle metabolites hydroxybupropion, erythrohydrobupropion and threohydrobupropion in human plasma. Separation of individual enantiomers (R)-bupropion, (S)-bupropion, (R,R)-hydroxybupropion, (S,S-hydroxybupropion), (1S,2S)-threohydrobupropion, (1R,2R)-threohydrobupropion, (1R,2S)-erythrohydrobupropion, and (1S,2R)-erythrohydrobupropion was achieved utilizing an α1-acid glycoprotein column within a 12-min run time. Chromatograph separation was significantly influenced by mobile phase pH and variability between columns. Analytes were quantified by positive ion electrospray tandem mass spectrometry following plasma protein precipitation with 20% trichloroacetic acid. Identification of erythrohydrobupropion enantiomer peaks and threohydrobupropion enantiomer peaks was achieved by sodium borohydride reduction of enantiopure (R)- and (S)-bupropion. Initial assay validation and sensitivity determination was on AB Sciex 3200, 4000 QTRAP, and 6500 mass spectrometers. Accuracy and precision were within 15% for each analyte. The assay was fully validated over analyte-specific concentrations using an AB Sciex 3200 mass spectrometer. Intra- and inter-assay precision and accuracy were within 12% for each analyte. The limits of quantification for bupropion (R and S), hydroxybupropion (R,R and S,S), threohydrobupropion (1S,2S and 1R,2R), and erythrohydrobupropion (1R,2S and 1S,2R) were 0.5, 2, 1, and 1ng/mL, respectively. All analytes were stable following freeze thaw cycles at -80°C and while stored at 4°C in the instrument autosampler. This method was applicable to clinical pharmacokinetic investigations of bupropion in patients. This is the first chromatographic method to resolve erythrohydrobupropion and threohydrobupropion enantiomers, and the first stereoselective LC-MS/MS assay to quantify bupropion, and principle metabolites hydroxybupropion, erythrohydrobupropion, and threohydrobupropion in human plasma.

Stereoselective method to quantify bupropion and its three major metabolites, hydroxybupropion, erythro-dihydrobupropion, and threo-dihydrobupropion using HPLC-MS/MS

Bupropion metabolites formed via oxidation and reduction exhibit pharmacological activity, but little is known regarding their stereoselective disposition. A novel stereoselective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to separate and quantify enantiomers of bupropion, 4-hydroxybupropion, and erythro- and threo-dihydrobupropion. Liquid-liquid extraction was implemented to extract all analytes from 50 μL human plasma. Acetaminophen (APAP) was used as an internal standard. The analytes were separated on a Lux 3 μ Cellulose-3 250×4.6 mm column by methanol: acetonitrile: ammonium bicarbonate: ammonium hydroxide gradient elution and monitored using an ABSciex 5500 QTRAP triple-quadrupole mass spectrometer equipped with electrospray ionization probe in positive mode. Extraction efficiency for all analytes was ≥70%. The stability at a single non-extracted concentration for over 48 h at ambient temperature resulted in less than 9.8% variability for all analytes. The limit of quantification (LOQ) for enantiomers of bupropion and 4-hydroxybupropion was 0.3 ng/mL, while the LOQ for enantiomers of erythro- and threo-hydrobupropion was 0.15 ng/mL. The intra-day precision and accuracy estimates for enantiomers of bupropion and its metabolites ranged from 3.4% to 15.4% and from 80.6% to 97.8%, respectively, while the inter-day precision and accuracy ranged from 6.1% to 19.9% and from 88.5% to 99.9%, respectively. The current method was successfully implemented to determine the stereoselective pharmacokinetics of bupropion and its metabolites in 3 healthy volunteers administered a single 100mg oral dose of racemic bupropion. This novel, accurate, and precise HPLC-MS/MS method should enhance further research into bupropion stereoselective metabolism and drug interactions.

Bupropion Hydrochloride

Bupropion hydrochloride is a norepinephrine-dopamine disinhibitor (NDDI) approved for the treatment of depression and smoking cessation. Bupropion is a trimethylated monocyclic phenylaminoketone second-generation antidepressant, which differs structurally from most antidepressants, and resides in a novel mechanistic class that has no direct action on the serotonin system. Comprehensive chemical, physical, and spectroscopic profiles are presented. This analytical profile provides an extensive spectroscopic investigation utilizing mass spectrometry, one- and two-dimensional NMR, solid-state NMR, IR, NIR, Raman, UV, and X-ray diffraction. The profile also includes significant wet chemistry studies for pH, solubility, solution, and plasma stability. Both HPLC and UPLC methodology are presented for bupropion and its related impurities or major metabolites. The profile concludes with an overview of biological properties that includes toxicity, drug metabolism, and pharmacokinetics.

Involvement of monoaminergic system in the antidepressant-like effect of (octylseleno)-xylofuranoside in the mouse tail suspension test

Depression is one of the most commonly diagnosed neuropsychiatric disorders and several studies have demonstrated a role for selenium in mood disorders. For this reason, the present study investigated the role of the monoaminergic system in the antidepressant-like action of (octylseleno)-xylofuranoside (OSX), an organoselenium compound, in the tail suspension test (TST) in mice. For this purpose, OSX (0.001–10 mg/kg) was administered orally (p.o.) 30 min prior to testing, and all of the tested doses reduced the immobility time in the TST without changing the locomotor activity measured in the open field test (OFT). Furthermore, the antidepressant-like effect of OSX (0.01 mg/kg, p.o.) in the TSTwas prevented by pre-treatment in mice with ketanserin (1 mg/kg, intraperitoneal route (i.p.); a 5-HT2A/2C receptor antagonist),WAY100635 (0.1mg/kg, subcutaneous (s.c.); a selective 5-HT1A receptor antagonist), p-chlorophenylalaninemethyl ester-PCPA (100mg/kg, i.p.; a selective inhibitor of tryptophan hydroxylase), prazosin (1 mg/kg, i.p.; an α1-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p.; an α2-adrenoceptor antagonist), SCH233390 (0.05 mg/kg, s.c., a dopaminergic D1 receptor antagonist) and sulpiride (50 mg/kg, i.p., a dopaminergic D2 receptor antagonist), but not with ondansetron (1 mg/kg, i.p.; a selective 5-HT3 receptor antagonist). Taken together, these data demonstrate that OSX has a potent antidepressant like effect in TST at lower doses (0.001–10 mg/kg), which is dependent on its interaction with the serotonergic, noradrenergic and dopaminergic systems.

Stereoselective Glucuronidation of Bupropion Metabolites In Vitro and In Vivo

Bupropion is a widely used antidepressant and smoking cessation aid in addition to being one of two US Food and Drug Administration-recommended probe substrates for evaluation of cytochrome P450 2B6 activity. Racemic bupropion undergoes oxidative and reductive metabolism, producing a complex profile of pharmacologically active metabolites with relatively little known about the mechanisms underlying their elimination. A liquid chromatography-tandem mass spectrometry assay was developed to simultaneously separate and detect glucuronide metabolites of (R,R)- and (S,S)-hydroxybupropion, (R,R)- and (S,S)-hydrobupropion (threo) and (S,R)- and (R,S)-hydrobupropion (erythro), in human urine and liver subcellular fractions to begin exploring mechanisms underlying enantioselective metabolism and elimination of bupropion metabolites. Human liver microsomal data revealed marked glucuronidation stereoselectivity [Cl(int), 11.4 versus 4.3 µl/min per milligram for the formation of (R,R)- and (S,S)-hydroxybupropion glucuronide; and Cl(max), 7.7 versus 1.1 µl/min per milligram for the formation of (R,R)- and (S,S)-hydrobupropion glucuronide], in concurrence with observed enantioselective urinary elimination of bupropion glucuronide conjugates. Approximately 10% of the administered bupropion dose was recovered in the urine as metabolites with glucuronide metabolites, accounting for approximately 40%, 15%, and 7% of the total excreted hydroxybupropion, erythro-hydrobupropion, and threo-hydrobupropion, respectively. Elimination pathways were further characterized using an expressed UDP-glucuronosyl transferase (UGT) panel with bupropion enantiomers (both individual and racemic) as substrates. UGT2B7 catalyzed the stereoselective formation of glucuronides of hydroxybupropion, (S,S)-hydrobupropion, (S,R)- and (R,S)-hydrobupropion; UGT1A9 catalyzed the formation of (R,R)-hydrobupropion glucuronide. These data systematically describe the metabolic pathways underlying bupropion metabolite disposition and significantly expand our knowledge of potential contributors to the interindividual and intraindividual variability in therapeutic and toxic effects of bupropion in humans.

Urinary Incontinence during Sleep Associated with Extended Release Form of Bupropion HCI

Bupropion hydrochloride (HCI) is an antidepressant that acts as a norepinephrine and dopamine reuptake inhibitor and has three different dosage forms including immediate release (IR), sustained release (SR), and extended release (ER). Despite its relatively safe side effect profile bupropion may cause several side effects. Here, we aimed to report a case with major depression using extended release form of bupropion hydrochloride who was presented with urinary incontinence during sleep, an uncommon side effect of bupropion.

Depression in Parkinson's disease: the effectiveness and risk of pharmacotherapy. Clinical review

Parkinson's disease (PD) is a neurological disease with a heterogeneous pattern of neurological symptoms and concomitant psychiatric syndromes. These syndromes are triggered by alterations to neurotransmission that are likely common for both neurological and psychiatric symptoms. Syndromes such as depression, anxiety, or cognitive impairment can precede motor symptoms of PD and delay its diagnosis. Recently, questions related to aetiological factors and treatment strategies of depression in PD have become a growing concern of PD researchers. This article describes the main features of depression in PD and presents current hypotheses on its aetiology and recommended treatment modes.

Insomnia and somnolence associated with second-generation antidepressants during the treatment of major depression: a meta-analysis

BACKGROUND

Sleep reduction or enhancement is frequently observed with second-generation antidepressant treatments, and they can be beneficial or harmful depending on the symptom profile of each subject. Nevertheless, relatively little attention has been given so far to rank those effects across compounds. The aim of this meta-analysis is to provide quantitative data about short-term rates of insomnia and somnolence associated with 14 second-generation antidepressants during the treatment of major depression.

METHODS

A literature search and a search of unpublished documents were performed. Eligible studies focusing on MD patients treated with second-generation antidepressants were entered in the analysis. Our primary outcome measures were insomnia and somnolence rates induced by antidepressants as compared with those associated with placebo. Sensitivity analyses were carried out as well.

RESULTS

Ten second-generation antidepressants showed higher rates of insomnia than placebo. The highest incidence was found for bupropion and desvenlafaxine. Agomelatine was the only antidepressant with a lower likelihood of inducing insomnia than placebo. Eleven antidepressants were associated with higher rates of somnolence than placebo. Fluvoxamine and mirtazapine showed the highest frequency of somnolence. Bupropion induced somnolence to a lower extent than placebo. Sensitivity analyses showed a degree of variation of those findings.

DISCUSSION

Antidepressants are associated with different insomnia and somnolence rates, mainly depending on their mechanisms of action. Despite some limitations, we underscore that the treatment-emergent insomnia and/or somnolence are frequent, and they could be used in clinical practice to face the specific needs of each patient.

Risk of seizures in transcranial magnetic stimulation: a clinical review to inform consent process focused on bupropion

OBJECTIVE

When considering repetitive transcranial magnetic stimulation (rTMS) for major depressive disorder, clinicians often face a lack of detailed information on potential interactions between rTMS and pharmacotherapy. This is particularly relevant to patients receiving bupropion, a commonly prescribed antidepressant with lower risk of sexual side effects or weight increase, which has been associated with increased risk of seizure in particular populations. Our aim was to systematically review the information on seizures occurred with rTMS to identify the potential risk factors with attention to concurrent medications, particularly bupropion.

DATA SOURCES

We conducted a systematic review through the databases PubMed, PsycINFO, and EMBASE between 1980 and June 2015. Additional articles were found using reference lists of relevant articles. Reporting of data follows Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

STUDY SELECTION

Two reviewers independently screened articles reporting the occurrence of seizures during rTMS. Articles reporting seizures in epilepsy during rTMS were excluded. A total of 25 rTMS-induced seizures were included in the final review.

DATA EXTRACTION

Data were systematically extracted, and the authors of the applicable studies were contacted when appropriate to provide more detail about the seizure incidents.

RESULTS

Twenty-five seizures were identified. Potential risk factors emerged such as sleep deprivation, polypharmacy, and neurological insult. High-frequency-rTMS was involved in a percentage of the seizures. None of these seizures reported had patients taking bupropion in the literature review. One rTMS-induced seizure was reported from the Food and Drug Administration in a sleep-deprived patient who was concurrently taking bupropion, sertraline, and amphetamine.

CONCLUSION

During the consent process, potential risk factors for an rTMS-induced seizure should be carefully screened for and discussed. Data do not support considering concurrent bupropion treatment as contraindication to undergo rTMS.

Information for physicians and pharmacists about drugs that might cause dry mouth: a study of monographs and published literature

BACKGROUND

Over three-quarters of the older population take medications that can potentially cause dry mouth. Physicians or pharmacists rarely inform patients about this adverse effect and its potentially severe damage to the teeth, mouth and general health.

OBJECTIVES

The objectives of this study were to (1) identify warnings in the literature about dry mouth associated with the most frequently prescribed pharmaceutical products in Canada; and (2) consider how this information might be obtained by physicians, pharmacists and patients.

METHODS

Monographs on the 72 most frequently prescribed medications during 2010 were retrieved from the Compendium of Pharmaceuticals and Specialties (CPS, a standard drug information reference for physicians and pharmacists), the National Library of Medicine's 'DailyMed' database, directly from the manufacturers, and from a systematic search of biomedical journals.

RESULTS

The CPS provided monographs for 43% of the medications, and requests to manufacturers produced the remaining monographs. Mentions of dry mouth were identified in 61% of the products (43% amongst CPS monographs; an additional 43% amongst manufacturers' monographs; 7% in the DailyMed database and 7% from biomedical journals); five medications had contradictory reports in different monographs.

CONCLUSION

Nearly two-thirds (61%) of the most commonly prescribed medications can cause dry mouth, yet warnings about this adverse effect and its potentially serious consequences are not readily available to physicians, pharmacists, dentists or patients.

Bupropion-induced inhibition of α7 nicotinic acetylcholine receptors expressed in heterologous cells and neurons from dorsal raphe nucleus and hippocampus

The pharmacological activity of bupropion was compared between α7 nicotinic acetylcholine receptors expressed in heterologous cells and hippocampal and dorsal raphe nucleus neurons. The inhibitory activity of bupropion was studied on GH3-α7 cells by Ca2+ influx, as well as on neurons from the dorsal raphe nucleus and interneurons from the stratum radiatum of the hippocampal CA1 region by using a whole-cell voltage-clamp technique. In addition, the interaction of bupropion with the α7 nicotinic acetylcholine receptor was determined by [3H]imipramine competition binding assays and molecular docking. The fast component of acetylcholine- and choline-induced currents from both brain regions was inhibited by methyllycaconitine, indicating the participation of α7-containing nicotinic acetylcholine receptors. Choline-induced currents in hippocampal interneurons were partially inhibited by 10 µM bupropion, a concentration that could be reached in the brain during clinical administration. Additionally, both agonist-induced currents were reversibly inhibited by bupropion at concentrations that coincide with its inhibitory potency (IC50=54 µM) and binding affinity (Ki=63 µM) for α7 nicotinic acetylcholine receptors from heterologous cells. The [3H]imipramine competition binding and molecular docking results support a luminal location for the bupropion binding site(s). This study may help to understand the mechanisms of actions of bupropion at neuronal and molecular levels related with its therapeutic actions on depression and for smoking cessation.

Drug safety evaluation of naltrexone/bupropion for the treatment of obesity

INTRODUCTION

Obesity is a known health risk for the development of several preventable diseases. Obesity-related metabolic alterations negatively impact different physiological mechanisms, which supports the rationale for the use of combined drug therapy. Naltrexone is an opioid antagonist for the treatment of opioid and alcohol dependency, whereas bupropion is a norepinephrine/dopamine reuptake inhibitor used to treat depression and smoking cessation. Although not effective as individual monotherapies for obesity, naltrexone and bupropion in combination produce weight loss and a metabolic profile beneficial for the potential treatment of obesity.

AREAS COVERED

This review examines the safety and antiobesity effects of naltrexone and bupropion alone and in combination. It reviews the results of four Phase III clinical trials of a novel fixed dose of sustained-released naltrexone/bupropion.

EXPERT OPINION

Naltrexone/bupropion has a greater weight loss efficacy than two FDA-approved medications, orlistat and lorcaserin. Although the weight loss produced by phentermine/topiramate is superior to naltrexone/bupropion, the safety profile of naltrexone/bupropion has less severe adverse effects. In addition, naltrexone/bupropion is well tolerated, with nausea being the most reported adverse event. Unlike other centrally acting medications, lorcaserin and phentermine/topiramate, naltrexone/bupropion has no abuse potential.

Clinical factors associated with weight loss outcomes after Roux-en-Y gastric bypass surgery

OBJECTIVE

Gastric bypass surgery is an effective therapy for extreme obesity. However, substantial variability in weight loss outcomes exists that remains largely unexplained. Our objective was to determine whether any commonly collected preoperative clinical variables were associated with weight loss following Roux-en-Y gastric bypass (RYGB) surgery.

METHODS

The analysis was based on a prospectively recruited observational cohort of 2,365 patients who underwent Roux-en-Y gastric bypass surgery from 2004 to 2009. Weight loss was stratified into three major phases, early (0-6 months), nadir, and long-term (>36 months). Multivariate regression models were constructed using a database of over 350 variables.

RESULTS

A total of 12-14 preoperative variables were independently associated (P < 0.05) with each of the temporal weight loss phases. Preoperative variables associated with poorer nadir and long-term weight loss included higher baseline BMI, higher preoperative weight loss, iron deficiency, use of any diabetes medication, nonuse of bupropion medication, no history of smoking, age >50 years, and the presence of fibrosis on liver biopsy.

CONCLUSIONS

Several variables previously associated with poorer weight loss after RYGB surgery including age, baseline BMI, and type 2 diabetes were replicated. Several others suggest possible clinical interventions for postoperative management of RYGB patients to improve weight loss outcomes.

Resolution of sleepiness and fatigue: a comparison of bupropion and selective serotonin reuptake inhibitors in subjects with major depressive disorder achieving remission at doses approved in the European Union

Unlike selective serotonin reuptake inhibitors (SSRIs), bupropion may be classified as a dual noradrenaline and dopamine reuptake inhibitor, a difference with potential implications for the treatment of residual sleepiness and fatigue in major depressive disorder (MDD). Post-hoc analysis of subjects with remitted MDD was performed on data pooled from six double-blind, randomized trials comparing the European Union (EU)-approved dose of ≤300 mg/day bupropion with SSRIs (sertraline, paroxetine or escitalopram) for the resolution of sleepiness and fatigue. Hypersomnia score was defined as the sum of scores of the Hamilton Depression Rating Scale (HDRS) items 22, 23, and 24; fatigue score as HDRS item 13 score; and remission as HDRS-17≤7. Similar proportions of bupropion- and SSRI-treated subjects achieved remission at study endpoint (169/343, 49.3% vs 324/656, 49.4%; last observation carried forward (LOCF), p=0.45). Fewer bupropion-treated remitters had residual symptoms of sleepiness (32/169, 18.9% vs 104/324, 32.1%; p<0.01) and fatigue (33/169, 19.5% vs 98/324, 30.2%; p<0.05). Bupropion-treated remitters also showed greater improvement (mean change from baseline) in sleepiness (p<0.05) and fatigue scores (p<0.01) at endpoint: benefits were evident from week 2 for sleepiness (p<0.01) and week 4 for fatigue (p<0.01). Bupropion treatment at the EU-approved dose of ≤300 mg/day may offer advantages over SSRIs in the resolution of sleepiness and fatigue in remitted MDD patients.

Weight considerations in psychotropic drug prescribing and switching

Our review describes potential weight-altering effects of psychotropic medications (antipsychotics, antidepressants, anti-anxiety medications, mood stabilizers, sedative-hypnotics, medications for attention-deficit/hyperactivity disorder, and other psychotropic medications) and offers guidance on switching a medication if its weight-altering effect becomes problematic. For second-generation antipsychotics, the risk of weight gain is high with clozapine and olanzapine, low with amisulpride, aripiprazole, and ziprasidone, and medium with other second-generation antipsychotics. Switching from a high-risk antipsychotic to a low-risk antipsychotic usually mitigates or reverses weight gain. For second-generation antidepressants, there may be modest weight loss with bupropion and modest weight gain with mirtazapine and paroxetine. Other second-generation antidepressants are weight neutral but individual variations can occur. If significant change in weight occurs, switching to or adding a low-risk second-generation antidepressant should be considered. Mood stabilizers include lithium, valproate, carbamazepine, lamotrigine, oxcarbazepine, and most second-generation antipsychotics. Risk of weight gain is high with lithium and valproate and low with carbamazepine, lamotrigine, and oxcarbazepine. Given the complexity of bipolar disorder and its management, a switch of a mood stabilizer would be best done by a psychiatrist. Benzodiazepines, non-benzodiazepine and melatonergic hypnotics, doxepin, and trazodone are weight neutral. Diphenhydramine may cause weight-gain and can be switched to a weight-neutral hypnotic if needed. Stimulants can cause varying degrees of weight loss and switching to atomoxetine or bupropion may reverse this problem. If that fails, switching to clonidine or guanfacine can be tried. Switching must be evidence-based and take into account status of the condition being treated, efficacy, side effect profile, potential drug-drug interactions, required laboratory monitoring and cost of the drug(s) being considered, and patient's pregnancy status or plan. Non-pharmacological interventions both for mental disorders and overweight/obesity must be fully availed.