EPIDEMIOLOGY OF OPIATE USE

Transcription

1 Opiate Dependence

2 EPIDEMIOLOGY OF OPIATE USE Difficult to estimate true extent of opiate dependence Based on National Survey of Health and Mental Well Being: 1.2% sample used opiates in last 12 months 0.2% sample opiate dependent 2:1 M:F (National Household Survey)

3 EPIDEMIOLOGY OF OPIATE USE Higher incidence of disrupted childhood Family history of substance &/or alcohol abuse High levels of co-morbidity Depressive disorders Other substance use disorders Personality disorders Anxiety disorders

4 Medical complications of Opiate Dependence IVDU Infective Abscess cutaneous brain Cellulitis Septicaemia SBE Blood-borne viruses Hep B&C HIV

5 Medical complications of Opiate Dependence IVDU Infective STD s Hep A

6 Medical complications of Opiate Drug effects Dependence Toxicity/Overdose (NB concomitant sedative use) Withdrawal symptoms Sexual dysfunction secondary to testosterone Rhabdomyolysis Trauma eg burns Other embolic phenomena

7 Aims of Treatment for Opiate Dependence Treatment can: ameliorate the dysfunction and distress reduce risks of disease and death Longer duration of treatment conveys greater benefit.

8 Treatment Options for Opiate Dependence Pharmacotherapy Psychological Interventions Rehabilitation Self Help Groups eg Alcoholics Anonymous

9 Pharmacotherapy Withdrawal Management Use of clonidine and other symptomatic treatments for opiate withdrawal Largely superseded with the introduction of buprenorphine a partial opiate agonist improved withdrawal completion rates used in inpatient and outpatient settings

10 Pharmacotherapy Maintenance Agonist treatment: Methadone Buprenorphine Antagonist Treatment Naltrexone

11 Agonist Treatment (Substitution) General principle includes replacing short acting (heroin) with long acting orally active drug (methadone/buprenorphine) Agonist does provide some positive reinforcement therefore increased retention in treatment Increase in tolerance reduces pleasurable effect of heroin

12 Aim is to achieve stability by Decreasing withdrawal symptoms Reducing the effectiveness of heroin Providing a structured environment Contact with health services

13 Methadone Full agonist - orally active Daily supervised dosing (intrusive) Aim for doses above 60mg/day Full agonist therefore increased risk of overdose during induction or with concurrent use of other sedatives Stigma

14 Methadone Studies have shown a reduction in: Morbidity Mortality Criminality Risk taking behaviour

15 Methadone Studies have repeatedly found: Increases in Employment rates Physical and psychological wellbeing Retention rates for treatment

16 Buprenorphine Partial agonist - dosed sub-lingually Alternate day supervised dosing possible for some patients Ceiling effect therefore safer in overdose with less respiratory depression Possibility of precipitated withdrawal if given to someone on full agonist too early Less stigmatised than methadone Similar benefits to methadone

17 ANTAGONIST THERAPY Blocks positive reinforcement of opiate use Relatively unsuccessful in opiate dependence mainly due to poor compliance Naltrexone: Daily dosing (50mg) - no supervision required No self reinforcing effects ie not addictive Risk of OD when naltrexone ceased and heroin use recommenced Risk of severe precipitated withdrawal if given to those on full agonists too early Rapid Opiate Detoxification generally not any better than buprenorphine withdrawal but greater morbidity Problem of acute pain management whilst on naltrexone

18 FINDINGS FROM RESEARCH ON MAINTENANCE TREATMENT Methadone has the best retention rates (44% at 6 months) Buprenorphine only marginally less. Naltrexone the worst retention rate (4% at 6 months). Based on NEPOD Data Continued illicit drug use comparable between methadone and buprenorphine. Lowest with naltrexone

19 Psychological Interventions Cognitive Behavioural Approaches: Motivational Interviewing Relapse Prevention Psychodynamic interventions not recommended as not efficacious during active opiate using stage

20 Rehabilitation Therapeutic Communities ie residential Length of stay is between 1-12 months Different philosophies include: CBT 12 step Religious/Christian

21 Rehabilitation Longer term rehabs tend to be run by lay therapists eg ex-addicts as well as trained staff Strict rules Those who complete programmes have good outcomes BUT High attrition rates

22 OUTCOME Annual mortality rate : 1-2% (20X rate of non drug user) Thorley found in a 10 year follow up of a clinic patient group that : 40% were abstinent 60% were actively using, imprisoned or dead

23 OUTCOME Of those abstinent a high percentage use either alcohol or have a polysubstance abuse pattern Generally the longer the period of abstinence the better the outcome however up to 1/3 of those abstinent for 3 years eventually relapsed

24 Factors associated with poor outcome Early age of onset Long history IVI abuse Early drop-out from treatment ASPD