A double-blind, placebo-controlled study of oral nalmefene for alcohol dependence.

BACKGROUND: Nalmefene is a newer opioid antagonist that is structurally similar to naltrexone but with a number of potential pharmacological advantages for the treatment of alcohol dependence, including no dose-dependent association with toxic effects to the liver, greater oral bioavailability, longer duration of antagonist action, and more competitive binding with opioid receptor subtypes that are thought to reinforce drinking. METHODS: A double-blind, placebo-controlled trial was conducted to evaluate the safety and efficacy of 2 doses of oral nalmefene for alcohol dependence. The 105 outpatient volunteers were abstinent for a mean of 2 weeks prior to random assignment to the placebo or 20- or 80-mg/d dose nalmefene groups for 12 weeks. Cognitive behavioral therapy was provided weekly during treatment. Self-reported drinking or abstinence was confirmed by determinations of breath alcohol concentration and by collateral informant reports. RESULTS: Outcomes did not differ between the 20- and 80-mg dose nalmefene groups. Significantly fewer patients treated with nalmefene than patients given placebo relapsed to heavy drinking through 12 weeks of treatment (P<.02), with a significant treatment effect at the first weekly study visit (P<.02). The odds ratio of relapsing to heavy drinking was 2.4 times greater with placebo compared with nalmefene (95% confidence interval, 1.05-5.59). Patients treated with nalmefene also had fewer subsequent relapses (P<.03) than patients given placebo. CONCLUSIONS: Treatment with nalmefene was effective in preventing relapse to heavy drinking relative to placebo in alcohol-dependent outpatients and was accompanied by acceptable side effects.

A double-blind, placebo-controlled pilot study to evaluate the efficacy and safety of oral nalmefene HCl for alcohol dependence.

A dozen studies have been published showing that opiate antagonists suppress alcohol drinking in animals, and two independent placebo-controlled, double-blind clinical trials of naltrexone found this agent was associated with decreased alcohol craving and consumption in alcohol-dependent patients. Nalmefene is a newer opiate antagonist that has a number of potential advantages over naltrexone in the treatment of alcoholism, including no dose-dependent association with liver toxicity and more effective binding to central opiate receptors. Consequently, a double-blind pilot study was conducted to gather preliminary data on the safety and efficacy of nalmefene for reducing alcohol consumption in alcohol-dependent subjects. Twenty-one alcohol-dependent subjects meeting admission criteria were randomly assigned to 12 weeks of double-blind treatment with 40 mg nalmefene, 10 mg nalmefene, or placebo, resulting in 7 patients/treatment group. Nalmefene was well tolerated, with no serious adverse drug reactions. The 40 mg group had a significantly lower rate of relapse (p < or = 0.05), and a greater increase in the number of abstinent days/week (p < or = 0.09), than the other treatment groups. A significant decrease in the number of drinks/drinking day was noted for both nalmefene groups (p < or = 0.04), but not for placebo. These results were supported by parallel decreases in ALT. These pilot data provide preliminary support for the hypotheses that nalmefene can be safely given to alcoholics, and that nalmefene may have a role in reducing alcohol consumption and preventing relapse, particularly at the 40 mg level. A full-scale study is underway to confirm these preliminary findings.

Changes in transaminases over the course of a 12-week, double-blind nalmefene trial in a 38-year-old female subject.

A 38-year-old female was drinking 30 drinks/week before entering a 12-week, double-blind study of nalmefene for the treatment of alcohol dependence. Liver function tests (LFTs) were within normal limits at baseline and week 4, but on week 8, the ALT showed a 7-fold increase, and the AST showed a 4-fold increase from baseline. A decision was made to continue study medication based on the patient's positive response to this therapy (i.e., achieving complete abstinence) and no known dose-dependent association with liver toxicity in over 1300 patients treated with nalmefene for other indications. LFTs were repeated serially to assess the trend of the LFT values. The patient achieved total abstinence over the course of the study period and at the 3-month posttreatment follow-up was continuing to maintain these gains from the study program, and her LFTs had returned to normal. A gradual return to normal in ALT and AST, while treatment with nalmefene continued, does not support the role of nalmefene as an hepatotoxin. Relapse to drinking was excluded because of normal values for the gamma-glutamyltransferase, and verification of sobriety by self-report, significant other, and breathalyzer. A virology panel ruled out the presence of viral hepatitis. Dietary intake before the elevation in LFTs contained elements that have established association with hepatocellular changes. The routine prescription of serial LFTs in alcoholism pharmacotherapy trials may be expected to reveal clinically nonsignificant elevations that could potentially be related to exogenous factors, such as dietary composition and should not be reflexively attributed to medication under investigation and/or drinking.

Immunologic abnormalities in chronic fatigue syndrome.

The chronic fatigue syndrome (CFS), formerly known as chronic Epstein-Barr virus syndrome, is a clinical state of some complexity and uncertain etiology. In order to characterize in a comprehensive manner the status of laboratory markers associated with cellular immune function in patients with this syndrome, 30 patients with clinically defined CFS were studied. All of the subjects were found to have multiple abnormalities in these markers. The most consistent immunological abnormality detected among these patients, when compared with normal controls, was low natural killer (NK) cell cytotoxicity. The number of NK cells, as defined by reactivity with monoclonal antibody NKH.1 (CD56), was elevated, but the killing of K562 tumor cells per CD56 cell was significantly diminished. Lymphoproliferative responses after stimulation with phytohemagglutinin and pokeweed mitogen were decreased in most patients when compared with those in normal controls, as was the production of gamma interferon following mitogen stimulation. Lymphocyte phenotypic marker analysis of peripheral blood lymphocytes showed that there were significant differences between patients with CFS and controls. There was an increase in the percentage of suppressor-cytotoxic T lymphocytes, CD8, and a proportionally larger increase in the number of CD8 cells expressing the class II activation marker. Most patients had an elevated number of CD2 cells which expressed the activation marker CDw26. The numbers of CD4 cells and the helper subset of CD4+CD29+ cells in patients with CFS were not different from those in controls. There was, however, a significant decrease in the suppressor inducer subset of CD4+ CD45RA+ cells. The number of B cells, CD20 and CD21, were elevated, as were the numbers of a subset of B cells which coexpressed CD20 and CD5. The patterns of immune marker abnormalities observed was compatible with a chronic viral reactivation syndrome.