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Addiction Treatment
as HIV Prevention
Charles P. O’Brien, MD, PhD
David Metzger, PhD
George E. Woody, MD
University of Pennsylvania
Treatment Research Center
Current AIDS epidemiology
• Approximately 33,000,000 living with HIV/AIDS
• Over 10,000,000 infections among IDU
• Outside of Africa, over 33% of all new infections are estimated to be attributable to injection drug use
• No estimates of the major role of alcohol and non-injection drug use such as crack cocaine
Predictors of seroconversion in Explore: drug and alcohol use
Drug N at baseline
No. of infections
Hazard ratio*
95% CI
Heavy alcohol** 419 41 1.87 1.24, 2.81
Amphetamines 527 67 1.93 1.41, 2.64
Alcohol or drugs before sex
2952 205 1.57 1.08, 2.27
* REF = no, light or moderate use of alcohol; no speed use; no use before sex
** Heavy alcohol = 4+ drinks every day or 6+ drinks on a typical day
IDUs as Percent of Total Registered HIV CasesEastern Europe and Central Asian Countries, 2007
Countries with Injection Driven Epidemics, OSI, 2008
Source: UNAIDS 2008 Report on the Global AIDS Epidemic
IDUs as Percent of Total Registered HIV CasesEast and South East Asian Countries, 2007
HIV prevention strategies for drug using populations
• Education about HIV transmission
• HIV counseling and testing
• Increased access to sterile injection resources and condoms
• Drug addiction treatment
• HIV treatment
Treatment Options for Opioid Addiction
• Outpatient drug free counseling- not effective
• Medication-free therapeutic community-• Expensive, not widely available, effective with
small proportion of patients
• Methadone-1964, national program 1971
• Partial agonist- BuprenorphineSuboxone (combination)
• Naltrexone oral, depot and implant
Methadone
• Full agonist• Cross tolerance with all opioids• Reduces craving• Prevents withdrawal• Prevents pleasure from other opioids• Low dose not effective
B 6 12 18 24 30 36 42 48 60 720%
10%
20%
30%
40%
50%
60%
13%18%
21%21%
39%
51%
In Treatment Out of Treatment Months
Six year HIV infection rates by treatment status at time of enrollment
SuboxoneBuprenorphine Combined with
antagonist
Reduces abuse potential
Bup 2 mg: Nal 0,5 mg
Bup 8 mg: Nal 2 mg
(*Bup 16 mg: Nal 4 mg)
(*Bup 32 mg: Nal 8mg)
*tested, not marketed
Ev
alu
ati
on
Comer and Collins,The Journal of Pharmacology and Experimental Therapeutics, 303(2), 695-703, 2002
Report good effects
BL 0h 0.5h 1.5h 2.5h 3.5h 24h 48h
0
10
20
30
40
50
60
Placebo
2 mg Bup
8 mg Bup
2 mg Bup/Nx
8 mg Bup/Nx
Treatment Options for Opioid Addiction
• Naltrexone effective in special populations
• Physicians, pharmacists, nurses
• Parolees, Probationers
• Countries where agonists are not available
• ADHERENCEOralDepotPellet implant
Opioid craving VAS scores: Change from baseline
P<0.0002
Percent opioid-free subjects, by visit
Note: “Opioid-free” is indicated by urine drug tests (negative for opioids), naloxone challenge results, and TLFB data. Weeks with missing urine test results were imputed as positive.
Weeks ≤4:Grace period
Weeks 5 to 24: Assessment period
Treatment Options for Alcoholism
• Outpatient drug free counseling- with self-help• Alcoholics Anonymous
• Medication-free therapeutic community-• Expensive, not widely available, effective with
small proportion of patients
• Naltrexone: oral, depot• Acamprosate• Topiramate (off label)
Treatment Options for Stimulant Addiction
Cocaine, MethamphetamineInjection, nasal, smoked
• No FDA approved medication• Outpatient counseling
• Cognitive Behavioral Therapy
Medications in clinical trials• Vigabatrin• Topiramate• Modafinil• Baclofen
Rate of needle sharing reported by In-Treatment IDUs compared to Out-of-Treatment IDUs
0
0.2
0.4
0.6
0.8
1
Selwyn et al
1987
Martin et al
1990
Klee et al
1991
Williams et al
1992
Longshore et al
1993
Metzger et al
1993
Stark et al
1994
Capplehorn et al
1995
Percent of subjects reporting injection prior to, during, and following methadone treatment
0
20
40
60
80
100
(Ball and Ross, 1991)
Injection
Prior to Tx Entry
Injection After Tx
Entry
Injection in Prior
Year
Injection in Prior Month
Injection in Year After Tx
Percent infected after 18 monthsby treatment status
Per
cen
tag
e
Metzger et al 1993
3.5% 4.5%
22%
Conclusions
• Data suggests effective treatments for drug users:
- recognize addiction as a chronic disease
- use pharmacologic and counseling interventions
- are accessible, acceptable, and affordable
Conclusions
• Behavioral and serologic data support the hypotheses that drug users in treatment:
- significantly reduce the frequency of use
- practice fewer risk behaviors
- have greater access to HIV treatment
- are more adherent to HIV care