A Randomized, Double-blind Placebo-Controlled Pharmacogenetic Study of Topiramate in European-American Heavy Drinkers

A Randomized, Double-blind Placebo-Controlled Pharmacogenetic Study of Topiramate in European-American Heavy Drinkers

The purpose of this study is to advance the effort to develop personalized pharmacotherapy for alcohol use disorders (AUDs). The investigators propose to conduct a 12-week, prospective, randomized clinical trial of the moderating effect of rs2832407 on the efficacy of TOP in reducing heavy drinking (HD) in 200 individuals of European descent with DSM-5 AUD. The investigators will stratify the randomization on genotype and oversample rs2832407*C homozygotes, the most TOP-responsive genotype, to ensure comparable numbers of patients in the four medication x genotype groups. The investigators will use daily data collection to examine changes in relevant process variables (e.g., alcohol expectancies) and their interaction with genotype and medication group as predictors of HD. The proposed study is innovative in that it will be the first prospective test of a pharmacogenetic hypothesis involving TOP; it will use daily reports to examine expectancies and how they interact with medication and genotype to predict HD; and it will enroll DSM-5 AUD patients whose goal is either to reduce or stop drinking, which will increase the study's external validity.

This is a 12-week, prospective, randomized clinical trial of the moderating effect of rs2832407 on the efficacy of topiramate in reducing HD in 200 individuals of European descent with DSM-5 AUD. The investigators will stratify the randomization on genotype and oversample rs2832407*C homozygotes, the most topiramate-responsive genotype, to ensure comparable numbers of subjects in the four medication x genotype groups. The investigators will compare the efficacy of topiramate to placebo in reducing the frequency of HDDs in subjects with AUD using a two-arm, parallel-groups design. Subjects will either have a goal of reducing their drinking to safe levels or abstinence.

The investigators will use daily data collection to examine changes in relevant process variables and their interaction with genotype and medication group as predictors of HD. At each visit, all subjects will receive Medication Management (Pettinati, Weiss et al. 2004), which was developed for the COMBINE Trial and which the investigators modified to be relevant for both reducing heavy drinking and promoting abstinence. Random assignment to treatment group and double-blind conditions will be maintained throughout the study. Raters will be trained in the reliable use of all assessments. The investigators will use serum GGTP and percent disialotransferrin (%dCDT), an improved assay for carbohydrate deficient transferrin, to validate subject reports. Following a one-week pre-treatment assessment period, subjects will receive 12 weeks of treatment, after which there will be a 6-day taper period, during which subjects will reduce their dosage of topiramate gradually and then discontinue it completely. Daily reports during the treatment period will be obtained using interactive voice response (IVR) to identify subjective correlates of medication effects and to monitor medication use. Following the 12-week treatment period, subjects will be asked to return to the clinic for 3-month and 6-month post-treatment follow-up visits to evaluate the durability of treatment effects.

Two hundred men and women of European descent will be randomized to study medication. Subjects will be recruited using referrals from treatment programs throughout Philadelphia; IRB-approved advertisements on mass transit, on local radio and television stations and in newspapers, social media, and broadcast email messages at institutions that offer such a service and by posting/distributing recruitment materials in community and college settings. Respondents will initially be evaluated by telephone prior to an in-person visit to the Treatment Research Center of the University of Pennsylvania Perelman School of Medicine. The investigators will select subjects based on their genotype to ensure comparable numbers of individuals who are rs2832407*C-allele homozygotes and A-allele carriers. The investigators will block randomize subjects to balance the groups on treatment goal (i.e., reduced drinking or abstinence).

Inclusion Criteria:

1. Determined to be physically healthy, based on medical history and physical examination and approval of the study physician
2. Age 18 to 70 years, inclusive
3. Self-identified European ancestry
4. Meets DSM-5 criteria for AUD
5. Average weekly ethanol consumption of >24 standard drinks for men and >18 standard drinks for women, with a weekly average of > 2 HDDs during the month before screening
6. Stated goal to reduce drinking to safe levels or to stop drinking
7. Able to read English at an 8th grade or higher level and no gross cognitive impairment
8. Willingness to nominate an individual who will know the subject's whereabouts to facilitate follow up during the study
9. Women of child-bearing potential (i.e., who have not had a hysterectomy, bilateral oophorectomy, tubal ligation or is less than two years postmenopausal): must be non-lactating and practicing a reliable method of birth control, and have a negative urine pregnancy test prior to the initiation of treatment. Examples of medically acceptable methods for this protocol include: the birth control pill, intrauterine device, injection of Depo-Provera, Norplant, contraceptive patch, contraceptive ring, double-barrier methods (such as condoms and diaphragm/spermicide), male partner sterilization, abstinence (and agreement to continue abstinence or to use an acceptable method of contraception, as listed above, should sexual activity commence), and tubal ligation.
10. Willingness to provide signed, informed consent and commit to completing the procedures in the study

Exclusion Criteria:

1. A current, clinically significant physical disease or abnormality on the basis of medical history, physical examination, or routine laboratory evaluation, including direct bilirubin elevations of >110% or a transaminase elevation >300% of normal
2. A history of nephrolithiasis
3. A history of glaucoma
4. Current treatment with carbonic anhydrase inhibitors, due to the added risk of metabolic acidosis.
5. Current, serious psychiatric illness (i.e., schizophrenia, bipolar disorder, severe or psychotic major depression, panic disorder, borderline or antisocial personality disorder, organic mood or mental disorders, eating disorder, or imminent suicide or violence risk)
6. Current DSM-IV diagnosis of dependence on a drug other than alcohol or nicotine
7. A history of hypersensitivity to topiramate
8. Current regular treatment with a psychotropic medication (e.g., benzodiazepines, antidepressants), which affect neurotransmitter systems, or a medication to treat alcohol dependence
9. Currently taking any tricyclic antidepressant (e.g., Adapin (doxepin), Anafranil (clomipramine), Elavil (amitryptyline), Pamelor (nortryptyline), Tofranil (imipramine), Sinequan (doxepin)
10. Urine drug screen positive for recent use of opioids, cocaine, or amphetamines (may be repeated once and if the result is negative on repeat it is not exclusionary)
11. Because co-administration of topiramate with dolutegravir reduced plasma concentrations of the antiretroviral through induction of CYP3A, the use of dolutegravir is exclusionary.
12. Judged by the principal investigator or his designee to be an unsuitable candidate for receipt of an investigational drug