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