Efficacy and Safety of High Dose Baclofen for Alcohol Dependence

Alcohol dependence (AD) is a common problem with significant health consequences. Treatment of AD is evolving to include both counseling methods and medications. Several medications have been discovered, that show efficacy in AD, e.g. naltrexone, acamprosate. However, the overall effect of existing medications is modest leaving a clear need for the development of new pharmacotherapies. The gamma-aminobutyric acid (GABA)-B receptor agonist baclofen has attracted attention as a potential new medication for AD based on preclinical data and early clinical trials. Baclofen is an FDA approved medication with an excellent safety profile even for patients with liver cirrhosis-a not uncommon consequence of AD. Questions have arisen with regards to the efficacy of baclofen and whether higher doses of baclofen are safe and more effective than the prior tested dose of 30 mg/ day. There is emerging evidence that severity of dependence is positively associated with baclofen response. The main goal of the present proposal is to test the efficacy and safety of 30 mg/d and 90 mg/d of baclofen compared to placebo controlling for severity of dependence as assessed by drinks/drinking day. A primary secondary goal will examine for an anxiolytic effect of baclofen. The study proposes to enroll 120 men and women with AD in a randomized, placebo-controlled trial to include at least 60 individuals with more severe AD (≥14 drinks/drinking day for men; ≥10 drinks/drinking day for women) with randomization to baclofen or placebo balanced for this variable. Baclofen will be titrated to 10 mg t.i.d over 3 days and to 30 mg t.i.d over 12 days and maintained at that level for 12 weeks and then downtitrated for a total study time of 16 weeks. Medical Management will be provided to encourage progress towards drinking goals and to enhance retention and compliance. Drinking patterns, anxiety levels, sleep patterns, craving for alcohol, gamma-glutamyl transferase (GGT) and carbohydrate deficient transferring (CDT) will be assessed. Trough blood levels of R & S-baclofen will be assessed in all individuals at week 4.

In summary, the present proposal is innovative and of clinical significance as it will test and compare standard and high-dose baclofen for efficacy and safety in individuals with AD. The proposal is adequately powered to test the primary hypothesis and provides good power to assess whether drinks/drinking day is predictive of baclofen response. Adequate power is also present to examine the anxiolytic effect of baclofen. Ascertaining the effects of standard and high-dose baclofen, the predictive value of heavy drinking on baclofen response and the anxiolytic effect of baclofen are important goals towards determining whether baclofen has true value for the clinical management of the patient with alcohol dependence.

Inclusion criteria

• Men and women between the ages of 18 and 65 meeting Diagnostic and Statistical Manual (DSM)-IV criteria for current alcohol dependence.
• More than 14 drinks (women) or 21 drinks (men) per week including at least 2 heavy drinking days (men > 5 drinks/day; women > 4 drinks/day) per week in the 30-day period prior to screening. In addition we will recruit 50% of individuals who have a mean of ≥14 drinks/drinking day (men) or ≥10 drinks/drinking day (women) in the 30 days prior to screening.
• Ability to understand and sign written informed consent.
• Must have a 0.0 gms/dL breathalyzer reading on the day of screening and 0.0 gms/dL on the day of randomization.
• Express a desire to achieve abstinence or to greatly reduce alcohol consumption
• Must have a stable residence and be able to identify an individual who could contact participant if needed.

Exclusion criteria

• Clinically significant medical disease that might interfere with the evaluation of the study medication or present a safety concern (e.g., renal insufficiency, cirrhosis, unstable hypertension, diabetes mellitus, seizure disorder). Clinically significant psychiatric illness including any psychotic disorder, bipolar disorder, severe depression, or suicidal ideation.
• Other substance abuse or dependence disorder other than nicotine or alcohol or cannabis abuse.

Occasional use of cocaine is acceptable.

• Concurrent use of any psychotropic medication including antidepressants, mood stabilizers, antipsychotics, anxiolytics, stimulants, or hypnotics with the exception of stable doses of antidepressants for one month. Concurrent use of anticonvulsants, insulin, or oral hypoglycemics.
• Prior history of adverse reaction to baclofen.
• Creatinine level > Upper Limit of Normal (ULN) or Estimated Glomerular Filtration Rate < age norm.
• aspartate aminotransferase (AST), or alanine transaminase (ALT) > 5 times ULN or bilirubin > 1.5 X ULN.
• Positive urine toxicology screen with the exception of cannabis. Individuals with positive cannabis screens will be excluded only if they have a history of cannabis dependence.
• Pregnant women and women of childbearing potential who do not practice a medically acceptable form of birth control (oral or depot contraceptive, or barrier methods such as diaphragm or condom with spermicidal).
• Women who are breastfeeding.
• Individuals requiring inpatient treatment or more intense outpatient treatment for their alcohol dependence.
• Participation in any clinical trial within the past 60 days.
• Court-mandated participation in alcohol treatment or pending incarceration.