A Phase 4 interventional study of Acamprosate calcium and Placebo in Alcohol Use Disorder, sponsored by National Institute on Alcohol Abuse and Alcoholism (NIAAA). Recruiting at 1 site in United States. Open to participants aged 21 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by National Institute on Alcohol Abuse and Alcoholism (NIAAA) · Phase 4, Interventional, and Basic science
Background:
Chronic heavy drinking can cause alcohol use disorder (AUD). AUD changes how the brain works. People with AUD may drink compulsively or feel like they cannot control their alcohol use. Acamprosate is an FDA-approved drug that reduces anxiety and craving in some, but not all, people with AUD.
Objective:
To learn more about how acamprosate affects brain function in people with AUD.
Eligibility:
People aged 21 to 65 years with moderate to severe AUD.
Design:
Participants will stay in the clinic for 21 days after a detoxification period of approximately 7 days.
Acamprosate is a capsule taken by mouth. Half of participants will take this drug 3 times a day with meals. The other half will take a placebo. The placebo looks like the study drug but does not contain any medicine. Participants will not know which capsules they are taking.
Participants will have a procedure called electroencephalography (EEG): A gel will be applied to certain locations on their scalp, and a snug cap will be placed on their head. The cap has sensors with wires. The sensors detect electrical activity in the brain. Participants will lie still and perform 2 tasks: they will look at different shapes and press a button when they see a specific one; and they will listen to tones and press dedicated buttons when they hear the corresponding tones.
Participants will have 2 EEGs: 1 on day 2 and 1 on day 23 of their study participation. They may opt to have up to 4 more EEG studies (one on day 13 and one on each of the three follow-up visits) and 2 sleep studies, in which they would have sensors attached to their scalp while they sleep.
Participants may have up to three follow-up visits for 6 months.
Study Description:
This double-blind placebo-controlled study will focus on electrophysiological changes in brains of alcohol use disorder (AUD)inpatients resulting from a post-withdrawal 21-day acamprosate/placebo treatment. Known and established electroencephalogram (EEG) markers of AUD as well as anxiety and alcohol craving levels will be assessed pre- and post-treatment. We hypothesize that acamprosate normalizes EEG markers associated with AUD beyond placebo, specifically, reduces beta power, increases alpha power, does not change slow band (delta and theta) power in resting EEG; and reduces theta event-related synchronization (ERS), and amplifies and hastens P300 waveforms in event-related potentials (ERPs).
Objectives:
Primary Objective: To test, via within-subject comparisons, whether a 21-day acamprosate treatment regimen normalizes the EEG of AUD inpatients beyond placebo in reducing beta power, increasing alpha power, and changing slow band (delta and theta) power in resting EEG; and reducing theta event-related synchronization (ERS), and amplifying and hastening P300 waveforms in event-related potentials (ERPs).
Secondary Objectives: 1) To correlate EEG changes with clinical changes, such as anxiety and alcohol craving. 2) To determine polysomnographic markers of response to acamprosate. 3) To correlate polysomnographic markers with clinical changes, such as anxiety and alcohol craving.
Endpoints:
Primary Endpoint: The said markers of EEG power and higher order EEG patterns will be measured before and after the 21-day treatment to compare the active-medication and placebo groups.
Secondary Endpoints: 1) Acamprosate-induced changes in EEG power and higher order EEG patterns will be correlated to changes in anxiety and alcohol craving. 2) Acamprosate-induced changes in EEG power will be correlated to changes in polysomnographic markers such as total sleep time, slow wave sleep duration, sleep efficiency, and total wake duration after sleep onset. 3) Changes in polysomnographic markers will be correlated to changes in anxiety and alcohol craving.
1,674 studies on the registry are indexed under Alcoholism; 331 are open to participants now.
This study's planned enrollment of 48 is below the median of 88 across 1,428 interventional studies indexed under Alcoholism.
Browse Alcoholism studies →National Institute on Alcohol Abuse and Alcoholism (NIAAA) is the lead sponsor of 102 studies on the registry; 14 are open to participants now.
Of its 13 completed or terminated interventional studies of FDA-regulated products, 9 (69%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
In order to be eligible to participate in this study, an individual must meet all of the following criteria:
EXCLUSION CRITERIA:
An individual who meets any of the following criteria will be excluded from participation in this study:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This arm has participants receiving acamprosate for 21 day as inpatients.
Drug: Acamprosate calcium
This arm has participants receiving placebo for 21 day as inpatients.
Other: Placebo
Two oral capsules (packaged as one) containing 666 mg of acamprosate calcium will be given three times a day (total daily dose: 1998 mg/day) for a total of 21 days.
Two oral capsules (packaged as one) containing 666 mg of inactive substance (e.g., sugar) will be given three times a day (total daily dose: 1998 mg/day) for a total of 21 days.
Reduction of beta power
Spectral power of EEG signals will be calculated in the beta frequency band (beta power). We expect a reduction of beta power to be greater in participants receiving acamprosate for 21 days than participants receiving placebo.
Time frame: 21 day period as inpatients
Promotion of alpha power in active group compared to placebo group.
Spectral power of EEG signals will be calculated in the alpha frequency band (alpha power). We expect a promotion of alpha power to be greater in participants receiving acamprosate for 21 days than participants receiving placebo.
Time frame: 21 day period as inpatients
No change in slow band (delta and theta) power in active group compared to placebo group.
Spectral power of EEG signals will be calculated in the delta and theta frequency bands (slow band power). We do not expect a significant difference in change in slow band power between the active and placebo groups over the course of 21 days.
Time frame: 21 day period as inpatients
Reduction of theta event-related synchronization in active group compared to placebo group.
Immediate brain activity, recorded via EEG, in response to task-related stimuli is termed as event-related potentials (ERPs). Spectral power of such ERPs in theta frequency band is called theta event-related synchronization (ERS).We expect a reduction of theta ERS to be greater in participants receiving acamprosate for 21 days than participants receiving placebo.
Time frame: 21 day period as inpatients
Amplification and hastening of P300 in active group compared to placebo group.
Immediate brain activity, recorded via EEG, in response to task-related stimuli is termed as event-related potentials (ERPs). These ERPs have stereotypical peaks, e.g., P300. We expect amplification and hastening of P300 peaks in ERPs among participants receiving acamprosate for 21 days in comparison to participants receiving placebo.
Time frame: 21 day period as inpatients
Correlation of EEG markers of acamprosate treatment with clinical measures of anxiety and alcohol craving
The above EEG measures that are found to be associated with acamprosate treatment will be tested for correlation with clinical measures of anxiety and alcohol craving.
Time frame: 21 day period as inpatients
Correlation of EEG markers of acamprosate treatment with polysomnography markers
The above EEG measures that are found to be associated with acamprosate treatment will be tested for correlation with polysomnography markers such as total sleep time, slow wave sleep duration, sleep efficiency, and total wake duration after sleep onset.
Time frame: 21 day period as inpatients
Correlation of polysomnography markers of acamprosate treatment with clinical measures of anxiety and alcohol craving
The above polysomnography measures that are found to be associated with acamprosate treatment will be tested for correlation with clinical measures of anxiety and alcohol craving.
Time frame: 21 day period as inpatients
Plan to share: Undecided — Study participant research data will include but not be limited to cognitive responses, EEG and PSG recordings, and cardiac and ocular activities (electronic data); and clinical and study assessments, and behavioral interviews (paper data). Individual participants and their research data will be identified by a unique study identification number. The key to link participants with their research data will be limited to the participating investigators, including the PI, lead associate investigator, and CNIRC research coordinators. Access to study data will be restricted to authorized personnel. De-identified data may be shared with collaborating researchers for data analysis.
Started May 2025 (actual). Primary completion is estimated for Dec 2026, 19 months after the start.
Of 24 phase 4 interventional studies under Alcoholism, half reached primary completion within 58 months of starting (the median), counting those still running; a quarter within 49 and three quarters within 83. This study's planned 19 months is below that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Acamprosate
National Institute on Alcohol Abuse and Alcoholism (NIAAA) →