In
Brief Ondansetron
for Alcoholics
Researchers at the University of Texas have found a potential new treatment for
some alcoholic patients: ondansetron, an anti-nausea drug best known for its use
in cancer chemotherapy. In a group of 271 alcoholic patients, equal
numbers were given ondansetron (at three different doses) or a placebo twice
daily for 2 1/2 months along with cognitive
behavioral therapy. The outcome was judged by a blood test for excessive alcohol
and by the reports of patients on their own symptoms. At the middle dose,
ondansetron proved effective for one group of patients, those with early-onset
alcoholism (before age 25) and a history of antisocial behavior. People with
these characteristics may have a biological predisposition to alcoholism, and
they often respond poorly to standard treatments. Ondansetron reduced their
drinking to one-sixth of its previous level, and they were abstinent on 70%
of days as compared with 50% of comparable patients taking a placebo. Unlike
disulfiram (Antabuse), ondansetron does not alter the breakdown of alcohol in
the body, so it is safer to take while drinking. In this study there were few
side effects; about 5% of the patients developed constipation or a headache,
rash, or racing heart.
The authors speculate that ondansetron changes the balance of activity among
several neurotransmitters, especially dopamine and serotonin. In particular, it
reduces activity at a certain serotonin nerve receptor; in animals, blocking
this receptor has been found to reduce the consumption of alcohol. Early-onset
alcoholics may carry a genetic variant of the receptor that makes them more
vulnerable to alcohol addiction.
The blood test used in the study is a new one. It measures a substance called
carbohydrate-deficient transferrin (CDT), which accumulates in the blood with
sustained heavy drinking and persists at high levels for several weeks even
after drinking stops. The FDA has recently approved the test: it will be given
to patients in alcohol treatment centers at first but may eventually be used
more widely.
Johnson BA et al. “Ondansetron for Reduction of Drinking among Biologically
Predisposed Alcoholic Patients: A Randomized Controlled Trial,” JAMA
(August 23/30, 2000): Vol. 284, pp. 963–71.
Combining ondansetron and naltrexone treats biological
alcoholics: corroboration of self-reported drinking by serum carbohydrate
deficient transferrin, a biomarker.
Ait-Daoud N, Johnson BA, Javors M, Roache JD, Zanca NA.
Department of Psychiatry and the Southwest Texas Addiction Research and
Technology (START) Center, University of Texas Health Science Center at San
Antonio, San Antonio 78229-3900, Texas, USA. tiouririne@uthscsa.edu
BACKGROUND: Recently, we showed by using self-report that combining ondansetron
(4 microg/kg twice a day) and naltrexone (25 mg twice a day) was effective
at reducing drinking and increasing abstinence among early-onset alcoholics
(EOAs), who are characterized by a range of antisocial behaviors and
high biological and familial disease predisposition. Here, we investigated
whether the self-reported differences in drinking would be corroborated by
measurements of serum carbohydrate-deficient transferrin (CDT) level, a
sensitive, reliable, and well-validated marker of transient alcohol
consumption. METHOD: An 8-week double-blind clinical trial was
performed in which 20 EOAs were randomized to receive ondansetron (4
microg/kg twice a day) and naltrexone (25 mg twice a day) or placebo as
an adjunct to weekly standardized cognitive behavioral therapy. Serum CDT
was assessed at weeks 0 (baseline), 4, and 8. RESULTS: Log serum CDT was
significantly lower in the ondansetron and naltrexone group (group mean,
1.44 +/- 0.076) compared with the placebo group (group mean, 1.82 +/-
0.113), as evidenced by a main effect of group [F(1,15) = 7.2, p = 0.017;
effect size = 0.32], visit [F(1,16) = 11.2, p = 0.004; effect size = 0.41],
and an interaction between group and visit [F(1,16) = 27.54, p < 0.001;
effect size = 0.63]. CONCLUSIONS: The combination of ondansetron plus
naltrexone was superior to placebo at reducing serum CDT. This corroborated
our self-reported drinking data and demonstrated that the medication
combination is an effective treatment for EOAs.
Combining ondansetron and naltrexone reduces craving
among biologically predisposed alcoholics: preliminary clinical evidence.
Ait-Daoud N, Johnson BA, Prihoda TJ, Hargita ID.
Treatment Research Center, Department of Psychiatry, University of Texas,
Health Science Center at San Antonio, 78229-3900, USA. tiouririne@uthscsa.edu
RATIONALE: Previously, we have reported that the combination of ondansetron
(a 5-HT3 antagonist) and naltrexone (a mu opioid antagonist) appears
to act synergistically at improving the drinking outcomes of early
onset alcoholics (EOA). a subtype of alcoholic characterized by
developing problem-drinking earlier, antisocial behaviors, high
familial loading, and biological disease predisposition. Presumably,
this medication combination counteracts the interaction between activated
central 5-HT3 receptors and the endogenous opioid system during the
mediation of alcohol-induced reward. We now hypothesize further that
an important mechanism by which the combination diminishes alcohol
consumption is through a reduction in craving. OBJECTIVE: To
determine whether the combination of naltrexone and ondansetron is
superior to a placebo at reducing craving among EOA, and the relationship
between craving and drinking behavior in both treatment groups. METHODS:
We conducted an 8-week double-blind placebo-controlled clinical trial
in which 10 EOA were randomized to receive ondansetron (4 microg/kg b.i.d.)
+ naltrexone (25 mg b.i.d.) and 10 EOA had a placebo (total n=20) as an
adjunct to weekly standardized group cognitive behavioral therapy.
Craving was measured by using the obsessive compulsive drinking scale (OCDS).
RESULTS: Craving ratings were scored on four subscales which where derived
empirically by principal component structure analysis of the OCDS. EOA who
received the medication combination, compared with the placebo, had
significantly lower scores on "automaticity of drinking" and
"alcohol consumption ". Reduction in automaticity of drinking
was correlated with self-reported drinking for only the medication
combination group. CONCLUSIONS: By reducing automaticity of drinking,
the medication combination presumably decreased drinking salience and
intensity. Larger scale studies testing these medications, both alone and
together, among alcoholic subtypes are needed to establish and extend
these promising findings.
Combining ondansetron and naltrexone effectively treats
biologically predisposed alcoholics: from hypotheses to preliminary clinical
evidence.
Johnson BA, Ait-Daoud N, Prihoda TJ.
Department of Psychiatry, University of Texas, San Antonio, USA. bjohnson@uthscsa.edu
BACKGROUND: Individuals considered to be early onset alcoholics (EOA)
are characterized by an early onset age, a broad range of antisocial
behaviors, high familial loading, and presumed biological disease
predisposition. Ondansetron, a 5-HT3 antagonist, improves drinking
outcomes and increases abstinence rates among EOA. Individuals with high
familial loading for developing alcoholism have lower levels of
beta-endorphin and demonstrate a more pronounced increase in beta-endorphin
levels in response to alcohol administration compared with individuals who
do not have alcoholic relatives. The propensity fornaltrexone
(a mu opioid antagonist) to reduce alcohol's rewarding effects and
drinking in humans is greatest in individuals with high familial loading.
Predicated on the added knowledge that 5-HT3 receptors may themselves
mediate alcohol reward via activation of the endogenous opioid system, we
hypothesized that the combination of ondansetron and naltrexone would act
synergistically and would be an effective treatment in EOA. METHODS: We
conducted an 8-week double-blind placebo controlled clinical trial in which
20 EOA were randomized to receive ondansetron (4 microg/kg twice a day) +
naltrexone (25 mg twice a day) or placebo as an adjunct to weekly
standardized group Cognitive Behavioral Therapy. RESULTS: At endpoint,
subjects who received ondansetron + naltrexone (n = 10), compared with those
who received placebo (n = 10), had fewer drinks/day (covariate adjusted mean
0.99 +/- 0.60 vs. 3.68 +/- 0.63; F1, 16 = 9.35,p = 0.008; effect size =
1.42), drinks/drinking day (covariate adjusted mean 3.14 +/- 0.87 vs. 6.76
+/- 0.71; F1, 13 = 10.45, p = 0.007; effect size = 1.71), and a trend toward
increased percent days abstinent (covariate adjusted mean 69.76 +/- 8.64 vs.
48.24 +/- 9.12; F1, 16 = 3.58, p = 0.08; effect size = 0.88). CONCLUSIONS: Ondansetron
plus naltrexone seems to synergistically improve the drinking outcomes of
EOA. Larger scale studies that test these medications, both alone and
together, among various alcoholic subtypes are needed to establish and
extend these promising findings.
Neuropharmacological treatments for alcoholism:
scientific basis and clinical findings.
Johnson BA, Ait-Daoud N.
Department of Psychiatry, University of Texas, Health Sciences Center at San
Antonio 78212, USA. bjohnson@uthscsa.edu
Preclinical studies have exploded our knowledge about the behavioral and
biological underpinnings of alcoholism. These studies suggest that
certain neurotransmitters, particularly those interacting with the opioid,
N-methyl-D-aspartate, and monoamine systems, may play a critical role in the
expression of alcohol-drinking and other behaviors associated with its abuse
liability. Built upon this foundation, important advances have been made
in the development of therapeutic medications for the treatment of
alcoholism. Of the medications reviewed, acamprosate's potential appears
to be the most widely established. In the USA, naltrexone was
approved by the Food and Drug Administration in 1995 for the treatment of
alcoholism; however, the results of some studies have been less
encouraging. Naltrexone's reliance on high compliance rates for efficacy
may, eventually, limit its potential in clinical settings offering generic
treatment for alcoholism. The relative paucity of dose-response studies on
naltrexone's effects in treating alcoholics is an important gap in the
literature. Recent data from a large clinical trial suggests that
ondansetron, a serotonin3 antagonist, offers new hope for the treatment of
early onset alcoholics; a type of alcoholism most difficult to manage with
psychosocial measures alone. Different subtypes of alcoholic may,
therefore, have varying treatment responses to serotonergic agents. Matching
subtypes of alcoholic to effective treatment medications based upon their
different biologies remains an important therapeutic goal. Combinations
of effective pharmacological agents need exploration as they may prove to be
synergistic, and could shepherd in a new era of treatments aimed at multiple
neurotransmitter targets associated with the alcoholism disease. The
coming decade promises more powerful tools for characterizing drug effects
on alcohol drinking, thereby closing the gap between animal models of
addiction and the human condition.
Department of Psychiatry and Human Behavior, Brown University, Providence,
Rhode Island, USA.
The use of medications as an adjunct to alcoholism treatment is based on the
premise that craving and other manifestations of alcoholism are mediated
by neurobiological mechanisms. Three of the four medications approved in
the United States or Europe for treating alcoholism are reported to reduce
craving; these include naltrexone (ReVia), acamprosate, and tiapride.
The remaining medication, disulfiram (Antabuse), may also possess some
anticraving activity. Additional medications that have been investigated
include ritanserin, which has not been shown to decrease craving or drinking
levels in humans, and ondansetron, which shows promise for treating early
onset alcoholics, who generally respond poorly to psychosocial treatment
alone. Use of anticraving medications in combination (e.g., naltrexone
plus acamprosate) may enhance their effectiveness. Future studies should
address such issues as optimal dosing regimens and the development of
strategies to enhance patient compliance.
University of Texas Health Sciences Center, San Antonio, USA.
Advances in neurobiology support the development of medications
to treat alcoholism by modifying the activity of specific chemical
messengers (i.e., neurotransmitters) in the brain. Among the most
promising new medications is acamprosate, which appears to decrease the
intensity of craving after a person has stopped drinking. Naltrexone (ReVia)
has been shown to decrease alcohol consumption, although its practical
effectiveness may be compromised by poor patient compliance and other
factors. Ondansetron shows promise for decreasing drinking and
increasing abstinence rates among early onset alcoholics, who respond
poorly to psychosocial treatment alone. Researchers are investigating
whether the use of specific medications in combination can further enhance
their effectiveness. Additional research is needed to determine how
medications interact with different psychosocial factors and treatments.