Latest medical literature on neobes

Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new neobes research articles will be listed here shortly after becoming available to us.

Medical research on neobes

Maternal fluoxetine treatment decreases behavioral response to dopaminergic drugs in female pups.

Neurotoxicol Teratol. 2008 May 14;
Favaro PD, Costa LC, Moreira EG
Since serotonin (5-HT) acts as neurotrophic factor, the use of fluoxetine (FLX) by mothers during pregnancy and/or lactation could disrupt brain development of the progeny. To unveil if maternal FLX exposure could compromise the functional integrity of monoaminergic and GABA-ergic neurotransmission, the behavioral responses of male and female mouse pups to diethylpropion, apomorphine, 8-OH-DPAT and diazepam were evaluated. Swiss dams were gavaged daily with FLX (7.5 mg/kg) or tap water during pregnancy day zero to weaning (postnatal day 21). Pups were evaluated on postnatal day 40. The behavioral response to diethylpropion was assessed in the open-field and drug-induced stereotyped behavior; to apomorphine in the drug-induced stereotyped behavior; to diazepam, in the elevated plus maze test and to 8-OH-DPAT in the open-field and forced swimming tests. Exposure to FLX did not influence any drug-induced behavioral response in males. Conversely, in females, FLX exposure significantly prevented diethylpropion-induced hyperactivity in the open-field and reduced stereotyped behavior induced by diethylpropion and apomorphine. In conclusion, the results showed that maternal exposure to FLX induced in female pups long-lasting decreased dopaminergic-mediated behaviors, suggesting altered development of the dopaminergic system. If this alteration also occurs in humans, female children of women who use FLX during pregnancy and lactation may express dopaminergic behavioral alterations and/or altered responsiveness to psychotropic medications later in life.

Weight loss medications--where do they fit in?

Aust Fam Physician. 2006 Aug; 35(8): 576-9
Dixon JB
BACKGROUND: Obesity is a chronic disease requiring a similar long term approach to management as that of other chronic conditions. OBJECTIVE: This article discusses the role of medications in the overall management of obesity. DISCUSSION: Management needs to be multifaceted, aiming to alter the patient and family micro-environment to one favouring better weight control through sustainable behavioural changes to physical activity and diet. Weight loss medications may provide additional benefit. Currently we have only two medications suitable for long term therapy--orlistat and sibutramine. Sibutramine, which acts centrally to suppress appetite, has shown efficacy for up to 2 years. Orlistat, a lipase inhibitor, reduces fat absorption and has been shown to reduce and maintain weight for up to 4 years. The effect of these medications is modest, generally providing less than 5 kg weight loss when compared with placebo. Patients need to have realistic expectations and understand the benefits of sustained modest weight loss. It is important that weight loss medications are prescribed in combination with lifestyle modification.

Safety of drug therapies used for weight loss and treatment of obesity.

Drug Saf. 2006; 29(4): 277-302
Ioannides-Demos LL, Proietto J, Tonkin AM, McNeil JJ
Some of the medications used for weight loss in the management of obesity have been associated with unacceptable morbidity and mortality. Safety concerns have led to the withdrawal of aminorex, followed by the fenfluramines in 1997, and phenylpropanolamine (norephedrine) in 2000. Aminorex was associated with an increased prevalence of primary pulmonary hypertension (PPH), fenfluramines with an increased prevalence of PPH and valvulopathy, and phenylpropanolamine with an increased risk of haemorrhagic stroke.Several studies have investigated the safety of the fenfluramines, yet the benefit-risk profile has not been conclusively quantified. This is due to several deficiencies in the published studies, including a lack of data on the baseline prevalences of comorbid conditions in obese subjects, and potential confounders and biases in the study designs. Although several studies and systematic reviews support an increased risk of PPH and valvulopathy in patients who have taken fenfluramines, without knowledge of the background prevalence it is not possible to determine if the exposure preceded the outcome. The population at higher risk of these adverse effects includes those taking higher doses or with a longer duration of exposure to fenfluramines and those with pre-existing cardiac disease or a genetic predisposition. Patients exposed to fenfluramines continue to be monitored, with some follow-up studies indicating no overall worsening in valvulopathy over time.There are limited efficacy and safety data for amfepramone (diethylpropion) and phentermine and their approval for the management of obesity is limited to short-term use. Orlistat and sibutramine are the only currently approved medications for long-term management of obesity. Although the benefit-risk profiles of sibutramine and orlistat appear positive, sibutramine continues to be monitored because of long-term safety concerns.The safety and efficacy of currently approved drug therapies have not been evaluated in children and elderly patient populations and there is limited information in adolescents, whilst the long-term safety of current and potential new drug therapies in adults will require several years of postmarketing surveillance to fully elucidate their adverse effect profiles.

[Drug treatment of obesity]

Ugeskr Laeger. 2006 Jan 9; 168(2): 163-7
Svendsen OL, Toubro S, Breum L, Bruun JM, Astrup AV
Acceptable adverse effects and a clinical relevant weight loss of 3 to 5 kilograms have been found in long-term randomized clinical trials for sibutramine (Reductil) and orlistat (Xenical); these drugs may be prescribed for treatment of obesity for a duration of one and four years, respectively. This also seems to be the case for rimonabant (Acomplia), which is expected to receive approval in 2005 or 2006. However, until data on morbidity and mortality are available from RCTs, there is no absolute indication for prescribing drugs for treatment of obesity.

Drug Insight: appetite suppressants.

Nat Clin Pract Gastroenterol Hepatol. 2005 Feb; 2(2): 89-95
Bray GA
The term 'appetite suppressant' is used to denote drugs that act primarily on the neurochemical transmitters of the central nervous system to reduce food intake. In addition to drugs that release or mimic the effect of norepinephrine (noradrenaline), this could include drugs that inhibit: reuptake of norepinephrine or 5-hydroxytryptamine (also known as serotonin); bind to the gamma-aminobutyric acid receptors or the cannabinoid receptors; and some peptides that reduce food intake. The sympathomimetic drugs phentermine, diethylpropion, benzphetamine, and phendimetrazine--so named because they mimic many effects of norepinephrine--are only approved in a few countries, and then only for short-term use. Sibutramine, a norepinephrine-5-hydroxytryptamine reuptake inhibitor, is approved for long-term use. Several new mechanisms for drug action are under investigation. Appetite suppressants should be viewed as useful adjuncts to diet and physical activity and might help selected patients to achieve and maintain weight loss.

Safety of obesity drugs.

Expert Opin Drug Saf. 2005 Nov; 4(6): 1083-95
Greenway FL, Caruso MK
The safety of obesity drugs has historically been poor. This and the stigmatisation of obesity in society ensured that a higher standard of safety for obesity drugs must be met. The authors review the safety disasters of obesity drugs that were withdrawn. The authors then review the safety of presently available drugs--benzphetamine, phendimetrazine, diethylpropion, phentermine, sibutramine and orlistat. The safety of rimonabant, a drug with a pending new drug application that has an independent effect on metabolic syndrome, is also reviewed. The authors compare the stage of obesity drug development to that of hypertension in the 1950s. As new and safer drugs with more downstream mechanisms are developed that have independent effects on the cardiovascular risks associated with obesity, third party reimbursement for obesity medicine is likely to improve. This may lead to obesity being treated like hypertension and other chronic diseases with long-term medication. With improved technological tools, the authors believe this process will be more rapid for obesity than it was for hypertension.

Obesity.

Clin Evid. 2005 Jun; 707-25
Arterburn D, DeLaet D, Flum D

Phentermine and anaesthesia.

Anaesth Intensive Care. 2005 Aug; 33(4): 525-7
Stephens LC, Katz SG
We describe the case of a woman who had two penroperative hypertensive crises that may have been due to her use of phentermine, a little-known sympathomimetic anti-obesity medication. The currently available anti-obesity medications are discussed: phentermine, diethylpropion, and sibutramine; all of which are sympathomimetics possessing noradrenaline and serotonin reuptake inhibitor activity. These medications should be discontinued one week preoperatively and have potential interactions with tramadol and antidepressants. The drug orlistat inhibits gastrointestinal lipase and may lead to fat soluble vitamin (A, D, E, and K) deficiency, so consideration should be given to checking coagulation status preoperatively.

Pharmacotherapy for obesity.

Drugs. 2005; 65(10): 1391-418
Ioannides-Demos LL, Proietto J, McNeil JJ
Pharmacotherapy for the management of obesity is primarily aimed at weight loss, weight loss maintenance and risk reduction, and has included thyroid hormone, amphetamines, phentermine, amfepramone (diethylpropion), phenylpropanolamine, mazindol, fenfluramines and, more recently, sibutramine and orlistat. These agents decrease appetite, reduce absorption of fat or increase energy expenditure. Primary endpoints used to evaluate anti-obesity drugs most frequently include mean weight loss, percentage weight loss and proportion of patients losing >or=5% and >or=10% of initial bodyweight. Secondary endpoints may include reduction in body fat, risk factors for cardiovascular disease and the incidences of diseases such as diabetes mellitus. Most pharmacotherapies have demonstrated significantly greater weight loss in patients on active treatment than those receiving placebo in short-term (

Meta-analysis: pharmacologic treatment of obesity.

Ann Intern Med. 2005 Apr 5; 142(7): 532-46
Li Z, Maglione M, Tu W, Mojica W, Arterburn D, Shugarman LR, Hilton L, Suttorp M, Solomon V, Shekelle PG, Morton SC
BACKGROUND: In response to the increase in obesity, pharmacologic treatments for weight loss have become more numerous and more commonly used. PURPOSE: To assess the efficacy and safety of weight loss medications approved by the U.S. Food and Drug Administration and other medications that have been used for weight loss. DATA SOURCES: Electronic databases, experts in the field, and unpublished information. STUDY SELECTION: Up-to-date meta-analyses of sibutramine, phentermine, and diethylpropion were identified. The authors assessed in detail 50 studies of orlistat, 13 studies of fluoxetine, 5 studies of bupropion, 9 studies of topiramate, and 1 study each of sertraline and zonisamide. Meta-analysis was performed for all medications except sertraline, zonisamide, and fluoxetine, which are summarized narratively. DATA EXTRACTION: The authors abstracted information about study design, intervention, co-interventions, population, outcomes, and methodologic quality, as well as weight loss and adverse events from controlled trials of medication. DATA SYNTHESIS: All pooled weight loss values are reported relative to placebo. A meta-analysis of sibutramine reported a mean difference in weight loss of 4.45 kg (95% CI, 3.62 to 5.29 kg) at 12 months. In the meta-analysis of orlistat, the estimate of the mean weight loss for orlistat-treated patients was 2.89 kg (CI, 2.27 to 3.51 kg) at 12 months. A recent meta-analysis of phentermine and diethylpropion reported pooled mean differences in weight loss at 6 months of 3.6 kg (CI, 0.6 to 6.0 kg) for phentermine-treated patients and 3.0 kg (CI, -1.6 to 11.5 kg) for diethylpropion-treated patients. Weight loss in fluoxetine studies ranged from 14.5 kg of weight lost to 0.4 kg of weight gained at 12 or more months. For bupropion, 2.77 kg (CI, 1.1 to 4.5 kg) of weight was lost at 6 to 12 months. Weight loss due to topiramate at 6 months was 6.5% (CI, 4.8% to 8.3%) of pretreatment weight. With one exception, long-term studies of health outcomes were lacking. Significant side effects that varied by drug were reported. LIMITATIONS: Publication bias may exist despite a comprehensive search and despite the lack of statistical evidence for the existence of bias. Evidence of heterogeneity was observed for all meta-analyses. CONCLUSIONS: Sibutramine, orlistat, phentermine, probably diethylpropion, bupropion, probably fluoxetine, and topiramate promote modest weight loss when given along with recommendations for diet. Sibutramine and orlistat are the 2 most-studied drugs.