Transcript Opioids - Part 1 - The University of Sydney

Opioids Part 1
Epidemiology of illicit use
Complications
Prescription opioid use
© 2010 University of Sydney
Learning Objectives
To be able to:
• Describe the prevalence of illicit opioid use and
dependence
• Understand the complications of injecting drug
use, including opioids
• Describe the prevalence of prescription opioid use
• Explain how to prescribe opioids responsibly to
reduce risk of iatrogenic dependence
Overview
• Epidemiology of illicit opioid use
• Factors affecting substance use
• Complications
– Psychosocial
– Medical
• Viral infections
• Overdose
• Prevention
• Prescription drug use
• Responsible prescribing of opioids
Mr. J
• Mr J, aged 24 , was recently released from jail
• Commenced illicit drug experimentation at age 12
• No home or major personal problems, just fell in with
friends that were ‘into things’
• Intermittent heroin use (mainly using stimulants) from
age 14 to 19, then daily heroin use; dependence
ensued
Questions:
– How common is heroin use?
– Who is more likely to develop problems with heroin?
– What are the associated risks?
Epidemiology of substance
abuse
• Prevalence
• Patterns of use
• Recent trends
Assessing Prevalence of Drug Use
• Household surveys of representative
samples
• Illicit Drug Reporting Scheme
– Utilises multiple sources of users and
their contacts
• Consequences
– Deaths, treatment seeking, crime
Life-time prevalence of drug
use in Australia 2007
100
80
60
40
20
0
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ha
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Percent (%)
Summary of drugs ever used:
proportion of the population aged 14 years or older
• Note: Heroin: 1.6% (0.3 million); Mean age of initiation of life-time use: 29 years.
• Household surveys underestimate use of stigmatised substances
Data Source: AIHW (2008) 2007 NDS Household Survey
Lifetime use of heroin
(by age and gender)
Lifetime use of heroin (2007)
3.5
3
Percent
2.5
Males
2
Females
1.5
Total
1
0.5
0
14-19
20-29
30-39
40+
Age
Data Source: AIHW (2008) 2007 NDS Household Survey
14+
Recent use of heroin
Use of heroin in the last 12 months (2007)
0.8
0.7
0.6
Percent
0.5
Males
0.4
Females
Total
0.3
0.2
0.1
0
14-19
20-29
30-39
40+
Age
Data Source: AIHW (2008) 2007 NDS Household Survey
14+
Recent use of heroin
• Males are more likely than females to
have used heroin in the last 12 months
– ♂ 0.3% vs ♀ 0.1%
– or ♂ 25,900 vs ♀ 10.300
• The highest proportion of recent users
found among 20-29 y.o. males
– 0.7% (10,700)
AIHW (2008) 2007 NDS Household Survey
Heroin - patterns of use
• Most users inject heroin
– However, a significant proportion ‘smoke’ heroin, inhaling
the vapour. Known as ‘chasing the dragon’
• Polydrug use is common
• Experimental and recreational use more common than
dependent use
– Risks - especially of Hep C and overdose
• Long-term dependent user has the largest impact on
public health and order
• Dependent use
– usually daily use by injection (1-2 years from 1st use to
daily use)
Heroin use among Injecting
Drug Users (IDUs)
• 2009 National sample: N=881
• Heroin is the drug of choice (52% of
IDUs)
– 64% of heroin users inject ~ 3 times a
week (in the last six months)
– 15% use daily
Stafford J., & Burns, L. Drug Trends Bulletin, December 2009. (NDARC)
Estimated number of heroin
dependent users in Australia
Data source: Degenhardt et al 2004, NDARC
Dependent heroin users
• Dependent heroin users
– 65% male; age varies (median 30-35 years);
evidence of aging cohort in Australia
– >90% English speaking
– Indigenous 10-15%
– Imprisonment ~50%
– Unemployment/pension >80%
– Homelessness ~10%
Day C, et al (2006) Drug Alcohol Rev. 25(4):307-13
Complications
Psychological
Social
Medical
Drugs
Psychosocial complications
of heroin use
• Generally severe. Why?
– Illicit
– Stigmatized
– Expensive
– Grossly intoxicating
(contrast with tobacco)
Social consequences
•
Illicit nature
– Imprisonment rate up to 50%
(60% of prisoners are incarcerated for drug-related crime, 20% for
alcohol-related crimes)
•
Stigmatised
– Alienation from parents, spouse and children
– Discrimination in workplace, health care
•
Expensive : $50-200 per day
– Involvement in crime (theft, dealing, importation)
– Prostitution
– Homelessness and debt to unscrupulous drug dealers predispose
users to becoming victims of violent crime.
•
Intoxication
– Inability to complete education or keep jobs
– Difficulties caring for children; family breakdown may result
Medical complications
• Non-specific to opioids
– Infections
• Viral*, bacterial, fungal
– Vascular damage
• Venous, arterial, pulmonary
– Glomerulonephritis
• Not common, but severe complication of injecting drug use
– Rabdomyolysis and acute renal failure
• Not common, but severe complication resulting from
compartment syndrome (caused by prolonged period of
unconsciousness)
– Malnutrition
– Trauma
* Major causes of harm - discussed in this topic
Medical complications (cont)
• Specific to opioids
– Overdose*
– Dental caries
• Mostly due to suppressed secretion of
saliva
• May cause acute or chronic pain, dental
infections
* Major causes of harm - discussed in this topic
Infections due to IDU
• Viral
– Caused by blood borne viruses (BBV)
– HIV/AIDS, Hepatitis C (HCV), Hepatitis B
(HBV)
• Bacterial
– Abscess, cellulitis, necrotising fasciitis,
thrombophlebitis
– Pneumonia
– Endocarditis: R>L sided, Staph Aureus
• Fungal
– Mostly Candida albicans, local or systemic
Viral Infections: Prevalence
in IDUs
Transmission of viral infections:
Needle sharing
• Sharing needles and other injecting equipment
or “works” (syringes, spoons, filters and bloodcontaminated water) is an important route of
transmission of the blood born viral infections
– Is three times more likely to transmit HIV than
sexual intercourse1
– Is the most common mode of HCV transmission2
– Is the most common risk factor for HBV in adults3
• Needle sharing has reduced with introduction of
Needle and Syringe Programs (NSP)
1Avert.org
(2009).
and NCHECR (2008) An overview of hepatitis C: Clinical management in opiate
pharmacotherapy settings.
3 Dore et al. (2005) Hepatitis B in Australia: Responding to a Diverse epidemic. (NCHECR)
2ASHM
Needle sharing (2004-2008)
Source: NCHECR (2009) Australian NSP survey: National data report 2004-2008
HIV antibody prevalence in IDUs
(Australia)
• HIV prevalence low: 1.5%
– Lower that in parts of USA, UK, Europe and Asia
– Reduced due to NSP, peer education and opioid
maintenance programs
• Prevalence is higher in:
– Homosexual males
– Predominantly methamphetamine users
(reporting as last drug injected), compared to
heroin
NCHECR (2009) Australian NSP survey: National data report 2004-2008
HIV prevalence by gender and
sexual identity
Source: NCHECR (2009) Australian NSP survey: National data report 2004-2008.
HIV prevalence by drug last
injected
NCHECR (2009) Australian NSP survey: National data report 2004-2008
HCV antibody prevalence in IDUs
• HCV prevalence high, stable at 62%
– Transmission reduced but not prevented by NSP
– Higher prevalence pre-NSP, compared to HIV
• Prevalence higher in users who are:
– Older that 30 years of age and with a longer history of
injecting
• 20% among those injecting for less than one year
• 50% - injecting for 8 or 9 years
• 75% - injecting for 20 years or longer
– Using predominantly heroin (reported as last drug
injected compared to those reporting
methamphetamine)
– Imprisoned in the year prior to survey
– From Indigenous background
NCHECR (2009) Australian NSP survey: National data report 2004-2008
HCV prevalence by years of IDU
NCHECR (2009) Australian NSP survey: National data report 2004-2008
HCV prevalence by drug last injected
NCHECR (2009) Australian NSP survey: National data report 2004-2008
Hepatitis B in IDUs1
• More than 40% of acute hepatitis B cases result
from unsafe use of injecting drugs
• Risk related to duration of injecting: up to 50%
HBVcAb+ in long term users
• Less government support compared to programs
aimed at reduction of HIV and HCV
• Vaccination of IDUs against HBV is available and
should be strongly recommended.
1 Dore
et al. (2005) Hepatitis B in Australia: Responding to a Diverse epidemic.
Intravenous Drug Use in prison
• High risk practices persist
– 75% continue some IDU in prison
– 80% share needles in prison (cf 20% in
community)
– 10% of prison-IDU started in prison
– High number of injecting partners
• 5 partners inside v 1 outside
Dolan, K. (1997) in Harm Reduction in Prison, Nedles & Fuhrer (Eds.);
Dolan, K. A. (2001) Medical Journal of Australia, 174, 378-379.
IDU in prison:
Confiscated needles and
syringes
Source: Mouzos J and Smith L (2007) Of Substance, 5(4):21.
Reprinted with permission.
Mental Health
Mental Health
• Mental health problems are common
among opioid users.
• Related to dependence and associated
lifestyle
• Complex relationship and interaction
between mental health and
dependence
Prevalence
• Prevalence of mental health problems
among opioid dependent treatment seekers
– Suicide
• 34% lifetime history of attempted suicide
• 13% attempted suicide in the last 12 months1
– Depression
• 25% reported current major depressive episode2
– Post traumatic stress syndrome (PTSD)
• 92% exposed to trauma
• 41% lifetime PTSD3
1
Darke, S. et al (2004) Drug and Alcohol Dependence, 73, 1-10.
Teesson, M. et al (2005) Drug and Alcohol Dependence, 78, 309-315.
3 Mills, KL et al (2005) Drug and Alcohol Dependence, 77, 243-249.
2
Opioid Overdose:
Risks and fatality rates
Opioid overdose
• Relatively common among heroin and
other opioid users
• Life-threatening
• Death from respiratory depression
Risk factors for opioid
overdose
• Polydrug use:
– Concurrent alcohol & benzodiazepines use
– Common in fatal and non-fatal overdoses
• Variable purity (not the major factor)
• Reduced tolerance to opioids
– e.g. recently released from prison, not on treatment
program
• Injecting alone (common in fatal overdoses)
• Not seeking help
– Absence of others or fear of police involvement
• Ineffective interventions often tried first by bystanders
Rates of heroin overdose
• High in Australia in 1997-1999
• Significant reduction in 2001,
consistent with reduced availability of
heroin
• Overdose remains a major cause of
heroin-related harm
Fatal opioid overdose rate
Source: Drug and Alcohol Office, Government of Western Australia (2008) Overview of Trends
in Opioid Related Mortality. Statistical Bulletin No. 40, February 2008, p.3.
Prevention of medical
complications
Preventing and reducing harm
from injecting heroin use
• Non-injecting route of administration
• Advice on safe injecting
– Professional or peer education
• Needle Syringe Programs (NSPs)
• Medically Supervised Injecting Centre
• Overdose interventions
• Hep B Vaccination
• Treatment programs
Needle and Syringe Programs
(NSP)
• One of the principal harm reduction measures
– Aim to curb the spread of HIV among injecting drug users
– First program established in Amsterdam in 1983
– Now exist in more than 40 countries
• Provide access to sterile syringes to reduce the risk of
IDUs coming into contact with other users’ infected blood
• Reduce the number of new HIV diagnoses without
encouraging drug use
• Have potential to increase recruitment into drug
treatment and into primary health care
WHO (2004) Effectiveness of Sterile Needle and Syringe Programming in Reducing HIV/AIDS
Among Injecting Drug Users.
NSPs in Australia
•
•
•
•
•
Commenced 1986
Widespread and publicly funded
Bipartisan support
General public support1
Fixed site, outreach, vending machines
and pharmacy
– Public, private and NGO operated
• Distribution rather than exchange
1Treloar
& Fraser (2007) Drug Alcohol Rev, 26: 355-361
NSP outcomes in Australia
• Number of distributed needles and syringes increased during
the past decade (from ~27 million to ~31 million)
• Needle sharing by IDUs reduced:
– ~30% of users in 19951
– ~10-20% in 2004, stable since then2
Effectiveness of NSPs (2000-08)2
• NSPs have directly averted:
• ~30,000 new HIV infections
• ~100,000 new HCV infections
• Annual national incidence of HIV and HCV among IDUs
decreased:
– HIV - from 39 to 24
– HCV - from ~13,000 to ~8,000
1NCHECR
2NCHECR
(2003) Australian NSP Survey National Data Report 1995-2002.
(2009) Australian NSP survey: National data report 2004-2008.
Overdose interventions
• Peer education
– Avoid polydrug use
– Avoid injecting alone
– Call an ambulance
• Naloxone administration
• Protocols to limit police intervention at
overdose resuscitation
• Supervised injecting rooms
Treatment Programs in Prison
• Assessment of dependence
• Management of intoxication and
withdrawal
• Education, counselling
• Opioid Treatment Programs (OTP)
– Those who remain in OTP 8/12 post release have significant reduction in
recidivism & mortality1&2
1Dolan,
2Dolan,
KA (2001) Medical Journal of Australia, 174, 378-379.
KA et al (2005) Addiction, 100, 820-828.
Prescription opioid use
and responsible
prescribing
Prescription opioid use
• Significant increase in number of prescriptions for codeine
in the 1990s, peaking in 1999, use now declining
• Dramatic rise in the use of oxycodone between 2001 and
20071
– Increasing steadily (by ~20% per year) since 2001
– Sharp increase in 2001-02 when generic oxycodone sustained
release became available
• Increase in the use of tramadol between 2001 and 2004
(plateau in 2004-2007)1
• Major harms:
– Spread of opioid dependence
– Risk of overdose
– Risks associated with non-sterile injection and needle sharing
1Leong
M et al (2009) Intern Med J, 39(10):676-81.
Illicit use of prescription
analgesics, including opioids
% population
6
Tranquillisers/sleeping
pills
5
4
Barbiturates
3
Pain killers/analgesics
2
1
0
1993 1995 1998 2001 2004 2007
Prevalence of prescription drug use for non-medical purposes (Use in the last
12 months, proportion of the population aged 14 years or older, Australia.)
Data source: AIHW 2008. 2007 National Drug Strategy Household Survey
Responsible prescribing of opioids
• Prolonged regular opioid use leads to
tolerance and risk of dependence
– Avoid use for chronic, non-terminal conditions
– Avoid parenteral opioids for recurrent conditions
such as migraine, back pain
– Be very cautious in prescribing opioids to
patients you don’t know
• BUT: do manage pain compassionately, even
in those with opioid dependence
Alternative treatments
• Non-steroid anti-inflammatory
analgesics
• Psychological and other management
of pain: e.g. via Pain Clinic
• Has the cause been adequately
treated?
• Consider a drug and alcohol referral for
iatrogenic dependence or mixed
iatrogenic/abuse picture?
Medical prevention issues
• Responsible prescribing
– Daily dispensing where potential for loss of control
over use
• Recognise and manage drug-seeking
behaviour
– Illegal to prescribe S8 drugs to patients with known
addiction to these drugs
– Say ‘no’ (promptly and courteously: ‘I’m not
allowed’, ‘I don’t prescribe … to patients I don’t
know’)
• Early referral to treatment in a D&A service
Legal controls on prescribing
(NSW)*
• Cannot prescribe opiates where there is
known dependence without an authority
• Methadone and buprenorphine for
opioid dependence
– Can only be prescribed by authorised
doctors (or nurse practitioners) and with
a NSW Health authority for each case
*It is important to check your local laws and all laws for accuracy, as they may
change.
Avoiding deliberate
misuse/diversion
• Scripts for opiates are usually faxed to
chemist if there is risk of tampering
• Dose in numerals and words
• Controlled dispensing (daily, weekly or
similar) from chemist or clinic makes dose
escalation or diversion less likely
– Can be arranged for any medication with a
willing pharmacy
– Sometimes a small fee involved
Case study: Jane
• Jane is aged 36, and presents because
panadeine forte (contains codeine 8mg)
is no longer controlling her back pain
• She is using 40 tablets per day
Questions:
– What are the risks of her panadeine forte
use?
– Can you suggest a better treatment?
Jane: Answers
• 40 tabs = approx 7 tabs every four hours
– Risk of paracetamol-induced hepatic damage
– Opioid dependence
• Jane would be better on a long-acting
opioid, if she is unable or unwilling to
cease: e.g. methadone or oxycontin
• Daily dispensing will help prevent dose
escalation
• Authority required
• Pain Clinic referral may be useful
Conclusion (1)
• Prevalence of heroin dependence in Australia is low
(<1%)
• Heroin use is associated with significant medical
and psychosocial complications, especially when
injected.
• Sharing of injecting equipment is the major vector
for transmission of blood bourn viral infections.
• Introduction of NSPs has prevented the epidemic of
HIV, but did not significantly reduce prevalence of
HCV infection in Australia
– Prevalence of HIV antibodies in IDUs is low
(1.5%)
– Prevalence of HCV antibodies remains high
(65%) but stable
• HBV antibodies are present in up to 50% of long
term IDUs
• Vaccination against HBV is strongly recommended.
Conclusion (2)
• Mental health problems are common among opioid
dependent people (e.g. depression, suicidal
ideations, PTSD)
• Opioid overdose is the major cause of heroin-related
harm
• Use prescription opioids with caution because
prolonged administration leads to tolerance and risk
of dependence
• Recognise and manage drug seeking behaviour
appropriately
• Provide adequate pain relief especially in people with
opioid dependence
Contributors
Associate Professor Kate Conigrave
Royal Prince Alfred Hospital & University of Sydney
Dr Ken Curry
Canterbury Hospital & University of Sydney
Dr Carolyn Day
University of Sydney
Professor Paul Haber
Royal Prince Alfred Hospital & University of Sydney
Dr Olga Lopatko
University of Sydney
Professor Richard Mattick
National Drug and Alcohol Research Centre,
University of New South Wales