Cerebral functional magnetic resonance imaging activation modulated by a single dose of the monoamine neurotransmission enhancers fluoxetine and fenozolone during hand sensorimotor tasks. (1/16)

Fluoxetine inhibits the reuptake of serotonin, and dextroamphetamine enhances presynaptic release of monoamines. Although the excitatory effect of both noradrenaline and dopamine on motor behavior generally is accepted, the role of serotonin on motor output is under debate. In the current investigation, the authors evidenced a putative role of monoamines and, more specifically, of serotonin in the regulation of cerebral motor activity in healthy subjects. The effects on cerebral motor activity of a single dose of fluoxetine (20 mg), an inhibitor of serotonin reuptake, and fenozolone (20 mg/50 kg), an amphetamine-like drug, were assessed by functional magnetic resonance imaging. Subjects performed sensorimotor tasks with the right hand. Functional magnetic resonance imaging studies were performed in two sessions on two different days. The first session, with two scan experiments separated by 5 hours without any drug administration, served as time-effect control. A second, similar session but with drug administration after the first scan assessed drug effects. A large increase in evoked signal intensity occurred in the ipsilateral cerebellum, and a parallel, large reduction occurred in primary and secondary motor cortices (P < 10(-3)). These results are consistent with the known effects of habituation. Both drugs elicited comparable effects, that is, a more focused activation in the contralateral sensorimotor area, a greater involvement of posterior supplementary motor area, and a widespread decrease of bilateral cerebellar activation (P < 10(-3)). The authors demonstrated for the first time that cerebral motor activity can be modulated by a single dose of fluoxetine or fenozolone in healthy subjects. Drug effects demonstrated a direct or indirect involvement of monoamines and serotonin in the facilitation of cerebral motor activity.  (+info)

Treatment of attention-deficit/hyperactivity disorder. (2/16)

OBJECTIVES: To determine (a) the long-term and short-term effectiveness and safety of pharmacological and nonpharmacological interventions for attention-deficit/hyperactivity disorder (ADHD) in children and adults and (b) whether combined interventions are more effective than individual interventions. SEARCH STRATEGY: MEDLINE (from 1966), CINAHL (from 1982), HEALTHStar (from 1975), PsycINFO (from 1984), EMBASE (from 1984), and the Cochrane Library searches were completed in November 1997. Reference lists of eligible studies and files of members of the research team and partner organizations were also searched. SELECTION CRITERIA: Studies were selected if they focused on the treatment of ADHD in humans and were published in any language as a full report in peer-reviewed journals. Studies including conditions other than ADHD were reported if separate subgroup analyses for patients with ADHD were provided. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data for 41 variables on general characteristics, along with detailed information on interventions, outcomes, and tests. Differences were resolved by consensus or by a third researcher. Studies were not combined quantitatively because the quality of reporting was low and heterogeneity existed across outcome measures and tests. MAIN RESULTS: Seventy-eight studies (77 randomized controlled trials) met the inclusion criteria. Twenty-three studies compared drugs and showed few, if any, differences among methylphenidate (MPH), dextroamphetamine (DEX), and pemoline; studies comparing stimulants with tricyclic antidepressants (2) were inconclusive. Six studies compared drugs with nondrug interventions and showed consistently that stimulants, particularly MPH, may be more effective than nonpharmacological interventions. Twenty studies compared combination therapies with a stimulant or a nondrug intervention alone; no additional beneficial effects for combination therapies were shown. Nine studies compared tricyclic antidepressants with placebo and showed that desipramine may be more effective than placebo; no consistent effect was shown for imipramine. Fourteen studies (13 in school children and 1 in adults) evaluated long-term therapy (> or = 12 weeks) and showed a trend to general improvement regardless of treatment, but the length of followup was inadequate. MPH may reduce behavioral disturbance in children with ADHD while it is taken. Academic performance does not appear to be improved with stimulants. Twelve studies evaluated treatment in adults with ADHD. For MPH vs. placebo, the results were contradictory. Antidepressants may be effective in adults, but no beneficial effect was seen with pemoline, nicotine, or phenylalanine compared with placebo. Thirty-two reports (29 studies) evaluated adverse effects of drug therapy; many of the side effects associated with stimulant use appear to be relatively mild and of short duration and to respond to dosing or timing adjustments. Data are inadequate on the long-term effects and severity of adverse effects of most interventions. CONCLUSIONS: This report describes rigorous systematic reviews on the treatment of ADHD, ready for incorporation into evidence-based clinical practice guidelines or performance measures. The report also provides a detailed description of the many limitations of the evidence available and provides recommendations to fill existing knowledge gaps. Studies on ADHD have low reporting quality, methodological flaws, and heterogeneity across outcome measures and tests. A detailed description is included of the many limitations of the available evidence plus recommendations to fill existing knowledge gaps. Fulfilling such knowledge gaps will not be easy and will require genuine collaboration among decisionmakers.  (+info)

Treatments for fatigue in multiple sclerosis: a rapid and systematic review. (3/16)

BACKGROUND: Multiple sclerosis (MS) is an important problem both for people with the disease and for society. There is no cure, and alleviation of symptoms forms the cornerstone of care. Excessive fatigue that severely limits activity is experienced by at least two-thirds of the estimated 60,000 people with MS in the UK. OBJECTIVES: (1) To identify current treatments for fatigue in MS and their evidence-base. (2) To systematically review the evidence for those treatments that have been investigated in more than one rigorous study, in order to determine their effectiveness and cost-effectiveness. METHODS: The review was carried out in two stages: a formal scoping review (to assess the range of interventions used by people with MS), and a systematic review for treatments that had been identified as promising and that had been investigated in clinical trials (as identified in the scoping review). A systematic review of research on costs and cost-effectiveness of those interventions identified as promising was also performed. Electronic databases, including MEDLINE and EMBASE, were searched for the period 1991-June 1999 (scoping review) and 1966-December 1999 (systematic review). Reference lists from publications were also searched, and experts were contacted for any additional information not already identified. RESULTS: Interventions identified for the treatment of fatigue in MS (1) Behavioural advice. This is the main element of initial clinical management and no rigorous research of its effectiveness was identified. (2) Drugs (amantadine, pemoline, potassium-channel blockers and antidepressants). (3) Training, rehabilitation and devices (cooling vests and electromagnetic fields). (4) Alternative therapies (bee venom, cannabis, acupuncture/acupressure and yoga). Only two drugs, amantadine and pemoline, met the criteria for full systematic review. RESULTS - EFFECTIVENESS OF AMANTADINE: One parallel and three crossover trials were found, involving a total of 236 people with MS. All studies were open to bias. All studies showed a pattern in favour of amantadine compared with placebo, but there is considerable uncertainty about the validity and clinical significance of this finding. This pattern of benefit was considerably undermined when different assumptions were used in the sensitivity analysis. RESULTS - EFFECTIVENESS OF PEMOLINE: One parallel and one crossover trial were found involving a total of 126 people with MS. Both studies were open to bias. There was no overall tendency in favour of pemoline over placebo and an excess of reports of adverse effects with pemoline. RESULTS - HEALTH ECONOMIC ANALYSIS: The drug costs of amantadine and pemoline are modest (pound 200 and pound 80 per annum, respectively). No economic evaluations were identified in the systematic review, and available data were insufficient to allow modelling of cost-effectiveness in this rapid review. CONCLUSIONS: There is insufficient evidence to allow people with MS, clinicians or policy makers to make informed decisions on the appropriate use of the many treatments on offer. Only amantadine appears to have some proven ability to alleviate the fatigue in MS, though only a proportion of users will obtain benefit and then only some of these patients will benefit sufficiently to take the drug in the long term. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH: The frequency, severity and impact of fatigue, the poverty of available research, and the absence of any ongoing research, suggest that new research is an urgent priority. People with MS, clinicians and policy makers should work together to ensure that the evidence required is collected as quickly as possible by encouraging involvement in rigorous research. Research should not be restricted to the two drugs reviewed in depth in this report. All interventions identified in the scoping review (see above) should be considered, as should basic scientific research into the underlying mechanism of fatigue in MS.  (+info)

Relative efficacy of drugs for the treatment of sleepiness in narcolepsy. (4/16)

A survey was conducted on 10 polysomnographic studies on the pharmacologic treatment of the sleepiness of narcolepsy. Three studies employed the MSLT and 7 employed the MWT as their polygraphic measure of sleep tendency. Statistically and clinically significant therapeutic changes were apparent for pemoline, modafinil, dextroamphetamine and methylphenidate. Codeine, ritanserin and protriptyline did show statistically significant effects. The common feature among the drugs that did produce clinically significant improvements seems to be facilitatory action on central catecholaminergic transmission. Within this group of drugs, only methylphenidate and dextroamphetamine brought MWT sleep latencies to approximately 70% of normal levels.  (+info)

Nifedipine suppresses self-injurious behaviors in animals. (5/16)

Self-injurious behavior is a common problem in many developmental disorders. The neurobiology of this behavior is not well understood, but the differing behavioral manifestations and associations with different disorders suggest that the underlying biological mechanisms are heterogeneous. The behavioral and biological heterogeneity is also evident in several animal models, where different manifestations can be provoked under different experimental conditions. Identifying commonalities among the different mechanisms is likely to be helpful in the design of treatments useful for the broadest populations of patients. The current studies reveal that nifedipine suppresses self-injurious behavior in 4 unrelated animal models: acute administration of high doses of +/-BayK 8644 or methamphetamine in mice, dopamine agonist treatment in rats with lesions of dopamine pathways during early development and repeated administration of pemoline in rats. The effect of nifedipine does not appear to be due to nonspecific mechanisms, such as sedation, since other classes of behaviors are unaffected or exaggerated. These results suggest that nifedipine may target a common biological mechanism in the expression of self-injurious behavior, and they suggest it should be considered in the treatment of self-injury in humans.  (+info)

Pemoline (2-amino-5-phenyl-1,3-oxazol-4-one)-induced self-injurious behavior: a rodent model of pharmacotherapeutic efficacy. (6/16)

Self-injury is a devastating, maladaptive behavior disorder that is common in developmental disabilities and is comorbid with numerous psychiatric disorders. Examples of self-injurious behavior (SIB) include head-banging, self-biting, and self-punching. The neurochemical basis of SIB is unknown; however, many different classes of drugs are prescribed (e.g., neuroleptics, atypical neuroleptics, anti-epileptics, opioid antagonists) to reduce these behaviors. These drugs have all shown clinically significant but limited efficacy in patient populations, and no class of drug is effective for all patients. The development and characterization of a valid animal model could provide important information regarding the neurochemical basis of SIB and could be used to screen potential new pharmacotherapies. In one model of SIB, high doses of pemoline (2-amino-5-phenyl-1,3-oxazol-4-one) are administered to rats. Using this model, we evaluated the effectiveness of three drugs (risperidone, valproate, and topiramate) that reduce SIB in humans. We also screened the potential effectiveness of tramadol, a drug that decreases stereotyped and compulsive behaviors but has not been assessed in human self-injurers. We found that risperidone, valproate, and topiramate each significantly attenuate pemoline-induced SIB, whereas tramadol does not. These findings suggest that the pemoline model of SIB has predictive validity across a range of drug classes and implicate important potential neurochemical mechanisms that may contribute to the behavior disorder. The findings also indicate that tramadol may not be an effective pharmacotherapy for SIB.  (+info)

The nonmedical use of prescription ADHD medications: results from a national Internet panel. (7/16)

BACKGROUND: Emerging evidence suggests that nonmedical use (NMU) of prescription attention deficit/hyperactivity disorder (ADHD) medications is rising, but many previous investigations have used clinical or regionally based samples or limited their investigations to stimulants rather than to medications specifically used to treat ADHD. Using an Internet-based epidemiological survey, this paper advances understanding of the prevalence and correlates of NMU of medications used to treat ADHD, sources of diverted medications, motivations for use, and consumption patterns. METHODS: The study used a self-administered Internet survey of civilian, noninstitutionalized adults (N = 4,297) aged 18 to 49 in the United States. National-level estimates were created using propensity scoring methods and weighting procedures using data from three nationally representative probability surveys: a random-digit dialed telephone survey, the current U.S. Census, and the National Survey on Drug Use and Health (NSDUH). RESULTS: Past-year prevalence of NMU of ADHD medications was approximately 2%, with 4.3% reported among those aged 18 to 25 and 1.3% among those aged 26 to 49. Most respondents reporting NMU used on multiple occasions. Receipt of medications for ADHD was a significant correlate of past-year NMU, though most nonmedical users never had a prescription. Among persons who had never been prescribed medication to treat ADHD, friends or family members were the most common source. Productivity was the most frequently endorsed reason for NMU. Alcohol was the substance most commonly used in combination with ADHD drugs. CONCLUSION: Because most prescription ADHD medications currently are highly regulated, policy options for supply-side reduction of nonmedical use may include identifying those medications with lower abuse liability for inclusion on insurance formularies. Patient and physician education programs also may be useful tools to heighten awareness of intentional and unintentional diversion of ADHD medications for nonmedical purposes.  (+info)

Psychostimulant treatment and the developing cortex in attention deficit hyperactivity disorder. (8/16)

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