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Pilot Study of Depot Naltrexone in Alcohol-Dependent, Homeless Veterans
Peter D. Friedmann, MD MPH
Providence VA Medical Center, Providence, RI
Funding Period: October 2010 - September 2011
A dearth of residential long-term rehabilitation beds makes an initial period of sobriety necessary in order for homeless persons to access needed transitional sheltering and to participate in outpatient alcohol treatment. Many alcohol-dependent homeless veterans find it difficult to achieve a period of sobriety, often 30 days to qualify for housing assistance. Clinical trials suggest that depot naltrexone is more efficacious than placebo in improving alcohol consumption among alcohol-dependent subjects, but depot naltrexone is expensive and has limited availability in many VA Medical Centers. Oral naltrexone is widely available but seldom used. This work seeks to examine the effect of depot versus oral naltrexone to help homeless alcohol dependent veterans reduce their drinking and qualify for housing assistance.
This open-label pilot study sought to compare the effect of 16-weeks of depot versus oral naltrexone among housing-seeking, alcohol dependent, homeless veterans. Outcomes included alcohol consumption, housing stability, emergency department and hospital utilization, and substance abuse treatment participation. These preliminary data sought to evaluate the feasibility and effect size to allow the design of a larger, more definitive study. That study would determine whether, compared to the oral naltrexone condition, the depot naltrexone group experiences greater proportion of days abstinent and fewer drinks per drinking day; shorter time to achieve 30 days sobriety; more improvement in housing stability; fewer emergency department visits and hospitalizations and greater attendance at substance abuse treatment (number of visits attended).
Over 5 months, we planned to recruit 20 homeless, alcohol dependent veterans at the Providence VA Medical Center from applicants for transitional or permanent housing. Potential candidates were identified primarily by the Homeless Coordinator at the Providence VA Medical Center who maintains the waiting lists for transitional or permanent housing at the Providence VA Medical Center. In person recruiting took place in the community and in the Homeless Clinic at the Providence VAMC. In some cases, recruitment letters were sent and flyers were posted within the medical center as well as in the community where the homeless frequent.
Using block randomization to stratify by current duration of abstinence (less than 7 days vs. 7 or more days) and sheltering (doubled-up/unsheltered/emergency vs. transitional sheltered), subjects were assigned to either injection with depot naltrexone 380 mg. monthly or oral naltrexone 50 mg daily for 16 weeks. All had medical visits with medication management counseling every 4 weeks with during the treatment period. Referrals were made to needed services in keeping with standard practice. Research assessments at baseline and every 4 weeks through week 24 used calendar-based interviews to assess alcohol consumption by self-report, breathalyzer and liver enzyme testing. Primary outcomes were alcohol consumption and time from randomization-to-30-day-sobriety. Secondary outcomes included housing stability (across 5 ordered categories), emergency department and hospital utilization, and alcohol treatment participation from administrative data, CPRS abstracting and self-report.
A research assistant approached 215 veterans for the study. Two hundred refused participation and 15 veterans were screened. The primary reason for refusal was not wanting to be injected with a medication. Other reasons were a specific fear of needles and not wanting to change their drinking habits.
Seven participants were consented and randomized. Of the remaining eight, five participants were excluded: one had cognitive impairment and delusions; two had pain conditions requiring opiates; one did not meet the homeless eligibility requirement; and one did not meet the criteria for alcohol abuse or dependence in the past year. Three screened in as eligible, but did not show up for the baseline interview and could not be located.
Of the seven who were randomized, three were randomized to the oral naltrexone group and four were randomized to the depot naltrexone (Vivitrol ) group. Participants were expected to attend monthly visits for six months which included the baseline visit, 4 treatment visits (weeks 4, 8, 12 and 16) and 2 follow-up visits (weeks 20 and 24). Three participants attended all seven (all three were in the oral naltrexone group). The remaining participant in the oral naltrexone group completed the baseline visit and follow-up weeks 4 and 8. For those in the depot naltrexone group, one attended the baseline visit and weeks 4, 8, 12 and week 16. Two participants completed the baseline visit only. Overall, those in the oral naltrexone group completed more visits than those in the depot naltrexone group. Almost all participants expressed a fear of needles which may have been a contributing factor to the majority of the oral naltrexone group completing the study (as well as to the low participation rate despite the diverse methods for recruitment).
Average age of the participants was 50. All were male. Three were living in transitional housing, two in drug and alcohol treatment facilities and two were unsheltered. Five participants classified themselves as Caucasian, one as African-American and one as both African-American and Caucasian.
BAC Levels were 0 at all appointments for all participants except for one individual on one visit date. Using a Timeline Followback Calendar (Sobell & Sobell, 2001), participants reported the number of drinks prior to each visit.
Participants in the depot group reported the following: one denied having any alcohol the month prior to baseline but did not return for another visit. Another remained sober until visit 16 and then was lost to follow-up. One participant reported drinking the equivalent of 85 drinks the month prior to baseline but did not return for future visits.
Participants in the oral naltrexone group reported the following: one participant reported entering the study sober and remaining sober throughout the entire length of the study. One reported drinking the equivalent of 495 standard drinks in the month prior to baseline, 891 drinks at week 4 (treatment week) and then 374 drinks at week 8 (treatment week). He did not return after week 8. One reported consuming the equivalent of 12 drinks in the month prior to baseline, 3 drinks at week 4 (treatment week), 4 drinks at week 8 (treatment week), 12 at week 12 (treatment week), 0 at week 16 (treatment week), 2 at week 20 (follow-up week) and 4 at week 24 (follow-up week). One participant denied having any alcohol with the exception of the month prior to week 8 in which he reported consuming the equivalent of 10 drinks.
The following symptoms were reported during weeks 4-24 but were not more common either group: dizziness on standing, headache, dry mouth, breathing trouble, nervousness, nausea, constipation, diarrhea, muscle aches, runny nose, weight gain, increased thirst, daytime tiredness, swelling of hands and feet, difficulty concentrating, confusion, morning drowsiness, daytime tiredness, runny nose, difficulty sleeping, feeling stressed. Overall, the medication appeared to be tolerated well. While participants stated that they experienced the above symptoms; they often stated that they did not attribute them to the medication but to other sources (e.g. having a head cold or feeling stressed because of their situation). One death occurred during the study; it was not study-related.
Effective medication-assisted treatment for the alcohol-dependent, homeless population could improve their substance use, health care utilization and housing stability. If depot naltrexone were a useful tool for engaging alcohol-dependent, homeless veterans in effective treatment, its effect would lead to fewer restrictions on depot naltrexone on the VA formulary, and expand access to effective medication-assisted treatment.
Unfortunately, despite approaching numerous alcohol-dependent, homeless veterans, the acceptability of depot naltrexone was limited. According to the local homeless coordinator and research assistant, the main reason for the refusals was the injection of medication. This was due to both founded and unfounded beliefs of being injected for study purposes. A specific fear of needles was ubiquitous among the participants, and some had concerns about "the government injecting (them) with something". Reluctance to change drinking habits was also seen in this population with high-severity alcohol dependence.
We conclude that depot naltrexone might be a useful tool for some alcohol dependent veterans, but the limited acceptability of a injectable medication constrains its widespread utility among homeless, alcohol-dependent veterans.
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NIH ReporterGrant Number: I01HX000444-01
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DRA: Mental, Cognitive and Behavioral Disorders, Substance Use Disorders
DRE: Treatment - Efficacy/Effectiveness Clinical Trial
MeSH Terms: none