sghms.ac.uk

The thermogenic and hypophagic effects of sibutramine's metabolite (metabolite 2), a 5-hydroxytryptamine (5-HT) and noradrenaline reuptake inhibitor, were investigated in rats and compared with duloxetine and bupropion. Metabolite 2 increased colonic temperature for 2.5-4.5 h. Duloxetine was also thermogenic but was less effective than metabolite 2. Bupropion similarly increased colonic temperature and was as efficacious, but less potent, than metabolite 2. At -8 degrees C, metabolite 2, duloxetine and bupropion all decreased response to heat reinforcement and reduced colonic temperature. Metabolite 2 produced a sustained increase in oxygen consumption (VO(2)) at 29 degrees C from 90 to 240 min, whereas duloxetine was far less effective. Bupropion rapidly enhanced VO(2), but its effect was less prolonged than that of metabolite 2. Metabolite 2 markedly reduced 24-h food intake. Duloxetine decreased feeding although its effect was shorter-lived, but bupropion was without effect. Thus, sibutramine's antiobesity action is probably attributable to effects on energy intake and expenditure. Duloxetine shares these properties, but is generally less efficacious. Any potential weight-reducing effect of bupropion is probably due to thermogenesis. Copyright 2002 Elsevier Science B.V.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12323384&dopt=Abstract Bupropion Wellbutrin




J Emerg Med. 2002 Oct;23(3):223-30.
Bupropion exposures: clinical manifestations and medical outcome.

Belson MG, Kelley TR.

Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA.

Bupropion is an antidepressant and smoking cessation aid. Limited toxicological information exists for intentional and unintentional bupropion-only exposures. A retrospective review of all bupropion-only exposures reported to the Toxic Exposure Surveillance System from 1998 through 1999 was conducted. Data for the three bupropion products, Wellbutrin, Wellbutrin SR, and Zyban, included demographics, reason for exposure, clinical effects, therapy, and medical outcome. A total of 7,348 bupropion-only exposures were reported: 56% female and 61% unintentional. The majority of exposures involved Wellbutrin SR; however, Wellbutrin exposures involved a higher percentage of intentional overdoses and serious clinical effects. Clinical effects related to bupropion were noted in 2,247 (31%) exposures; 8% of all children <6-years-old compared to 46% of all teenagers. Seizures developed in 15% of all intentional exposures. Cardiovascular disturbances were extremely uncommon after overdose. The majority of unintentional bupropion-only exposures result in minimal or no clinical toxicity; however, a significant number of intentional overdoses result in seizures. Copyright 2002 Elsevier Science Inc

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12426011&dopt=Abstract Bupropion Wellbutrin

iop.kcl.ac.uk

RATIONALE: The clinical success of the antidepressant bupropion, marketed as Zyban in smoking cessation, presents an ideal opportunity to unravel its mechanism of action utilising animal models of nicotine dependence. OBJECTIVE: The present experiments utilise bupropion as a reference compound to examine putative interactions with stimulus properties of nicotine in rats. METHODS AND RESULTS: In male hooded Lister rats, bupropion (10 and 30 mg/kg IP) administered 30 min prior to each intravenous nicotine (0.03 mg/kg per infusion) self-administration session failed to attenuate rates of nicotine intake. Moreover, following the large dose of bupropion, nicotine intake was enhanced and response rates remained elevated throughout the 28-day course of treatment. To examine interactions with subjective effects of nicotine, rats trained to discriminate nicotine (0.2 mg/kg SC) from vehicle were tested with bupropion (1, 3, 10 and 30 mg/kg IP). Bupropion pre-treatment failed to exert a "nicotine-like" action and also failed to attenuate the orderly dose-related discrimination function of nicotine (0.05-0.4 mg/kg SC) in rats. Using the conditioned taste aversion procedure to assess the aversive stimulus properties of nicotine, a function implicated in the regulation of nicotine intake, bupropion (3, 10 and 30 mg/kg IP) pre-treatment failed to modify the aversive effects produced by a threshold dose of nicotine (0.2 mg/kg SC). CONCLUSIONS: The results obtained with bupropion in these animal models of dependence suggest this antidepressant may not directly interact with stimulus properties of nicotine; rather its clinical efficacy may be exposed in animal models that are based upon chronic




J Urol. 2003 Jan;169(1):386-9.
Direct evidence of facilitative actions of dopamine in the medial preoptic area on reflexive and noncontact erections in male rats.

Adachi H, Sato Y, Kato R, Hisasue S, Suzuki K, Masumori N, Itoh N, Tsukamoto T.

Department of Urology, Sapporo Medical University School of Medicine S-1, W-16, Chuo-ku, Sapporo 060, Japan.

PURPOSE: We examined the effects of alterations of the extracellular dopamine level in the medial preoptic area on 2 erectile contexts, namely reflexive and noncontact erections, in male rats. MATERIALS AND METHODS: The extracellular dopamine level was measured in the medial preoptic area after administering the dopamine reuptake inhibitor bupropion hydrochloride (Sigma Chemical Co., St. Louis, Missouri) into the same area through a micro-dialysis tube. We measured the frequency and latency of reflexive erections, and the frequency of noncontact erection during infusion of bupropion. RESULTS: Administration of 10 mM. bupropion was associated with significant elevation in the extracellular dopamine level in the medial preoptic area. Bupropion (1 mM.) and Ringer's solution did not induce significant alterations in dopamine in the medial preoptic area. The number of reflexive erections significantly increased and erection latency decreased during infusion of 10 mM. bupropion into the medial preoptic area. The number of noncontact erections was also increased by administering 10 mM. of drug. CONCLUSIONS: The altered dopamine level in the medial preoptic area affected 2 distinct penile erectile contexts, suggesting that the dopamine levels in the medial preoptic area may be involved in the regulation of erection. These results may have important implications for the central regulation of penile erection.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12478196&dopt=Abstract Bupropion Wellbutrin

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OBJECTIVE: To investigate the toxicity of bupropion hydrochloride in deliberate self-poisoning in adults and accidental ingestion by children. DESIGN AND SETTING: Prospective study of cases identified from calls to the New South Wales Poisons Information Centre (NSW PIC), with follow-up through hospital medical records. PARTICIPANTS: Patients with bupropion poisoning managed in hospital, about whom the NSW PIC was contacted for advice, from 1 November 2000 to 31 July 2001 (59 adults and 10 children). MAIN OUTCOME MEASURES: Clinical effects, adverse outcomes (including seizures and death) and treatment. RESULTS: 45 of the 59 adults were followed up (76%), 19 of whom had taken bupropion alone. Major clinical effects of bupropion included sinus tachycardia (83%), hypertension (56%), seizures (37%), gastrointestinal symptoms (37%) and agitation (32%). Seizures were dose-dependent, with those having seizures ingesting a significantly higher median dose (P = 0.02). All seizures were brief and self-limiting. 29 patients received decontamination therapy. 10 patients required pharmacological sedation, 10 were admitted to intensive care and six were intubated. None died. Eight of 10 accidental ingestions by children were followed up (80%); one child had symptoms (vomiting and hallucinations). CONCLUSIONS: Bupropion overdose caused significant clinical effects in adults, but few in children.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12526723&dopt=Abstract Bupropion Wellbutrin