opioid_dependence
Table of Contents
opiate and opioid dependence
see also:
- WH patient information sheets (intranet only)
Heroin use
- comes as white or brown powder which is usually heated on a spoon and then injected or smoked
- 10 points = 1 g
- most users use 1 point at a time
- even 1 point a day is likely to lead to withdrawal symptoms on cessation
- 3 points per day is significant use, 5-10 points a day is very high use
- has a relatively short half life, patients presenting with opioid intoxication may self recover in time and without pharmacological intervention
- risk of fatal overdose due to respiratory depression is increased if the patient uses a higher amount than their tolerance and/or if mixed with other substances such as alcohol
- this is usually readily treated with naloxone - either intranasal, IM or IV
History in Australia:
- heroin injecting commenced in Australia in the late 1960's
- by 1997, it was estimated there was ~70,000 heroin-dependent persons with a rapid increase over the past few years associated with cheaper heroin
- deaths from heroin overdose has increased from 6 in 1964 to 600 in 1997 and 737 in 1998
- HIV / AIDS remains under good control amongst heroin injectors but ~11,000 cases of hep C in 1997 were attributed to sharing of injection equipment
- heroin dependency is a poorly understood, chronic relapsing condition
- mortality is 1-2% per year which is ~15 times that for similar age & sex population
- a UK study in 2005 showed that of those that took heroin “regularly” at less than 3x per week, on average it took 9 months for them to become physically dependent and use it daily. The actual time for physical dependence depended on a complex interaction of social factors (eg. living with a dependent person accelerated dependence), personality and context in which people use the drug. None became instantly addicted, some took as little as 5-6 months, while others took 5 years before becoming physically dependent.
Benefits of treatment of heroin dependence:
health:
- reduction in deaths
- reduction in morbidity - hep C, hep B, HIV, bacterial infections (abcesses, SBE), non-fatal overdoses
- improvement in mental health
social:
- improved relationships & parenting
- reduction in crime
- increased employment
- improved residential status (ie. less homelessness)
- increased education & training
- reduction in all sorts of drug usage
- reduction in heroin use
economic:
- earning income legally, or social security
- less debt
- benefits outweigh costs to individuals & society
Drug Treatment of Opioid Dependence:
initial detoxification:
- most is provided in residential care but outpatient detox. is increasing, though not all are suitable or willing for this approach.
- relapse is common and should not be cause for despair, but should be Rx by further detox. or other Rx forms ASAP.
- usual detoxification is a combination Rx of (this can also be used for inadvertent naltrexone usage causing withdrawal):
- IV fluids
- anti-emetic:
- prochlorperazine (Stemetil) 12.5mg i.v., repeat once if no effect
- ondansetron 4mg i.v. if prochlorperazine ineffective
-
- helps ameliorate some of the more distressing symptoms of heroin withdrawal
- dose: 75-150 mcg orally when vomiting controlled, or up to 300mcg i.v. titrated to effect (monitor BP)
- if cease clonidine abruptly may get rebound hypertension
- lofexidine is similar but with less CVS adverse effects but not available in Aust. yet.
-
- for bone pain
- diphenoxylate or lomotil:
- for diarrhoea
-
- for abdominal cramps
- dose: 20mg slow i.v. titrated to effect
-
- for short term Rx of insomnia
- if uncontrollable delirium, then consider:
- rapid sequence induction anaesthesia, usually using propofol infusions
accelerated detoxification:
- Ultra Rapid Opiate Detoxification (UROD)
- Rapid Opiate Detoxification (ROD)
- both currently experimental and require general anaesthesia or heavy sedation.
maintenance:
-
- an opioid agonist which is well absorbed orally with a long half-life allowing once daily dosing
- introduced in Australia for Rx of heroin dependence in 1964
- pts attend a clinic or pharmacy each day to be given a supervised dose
- detoxification is not required for pts starting methadone
- psychosocial interventions are an important adjunct
- as many as 85% will stay on methadone for 12mths & most require Rx for at least 2 yrs
- pts retained in Rx on a larger dose & for a longer duration generally achieve better results
- optimal dose is 60-100mg/day
- important Rx factors include optimal dosing & the morale of clinic staff
- programs are not available in the NT
-
- a long acting opioid antagonist which is well absorbed orally
- a severe withdrawal reaction may be precipitated if the pt has recently taken heroin or another opioid
- thus should not be started until 7-10days after last opioid dose
- dose: usually 50mg per day
- best results are obtained with “motivated” pts (eg. white-collar professionals, persons on parole, probation or in jail)
- if it is taken intermittently & then heroin is taken in the intervening periods, the risk of death from overdose may be INCREASED due to the reduced opioid tolerance.
- has also been found useful to decrease craving in chronic alcoholics undergoing withdrawal treatment
-
- a partial mu agonist and weak kappa antagonist taken sublingually as it has a high 1st pass metabolism
- half-life 4-5hrs
- ceiling effect:
- because it is a partial agonist, its effects plateau at higher doses & then begins to behave more like an antagonist which limits its maximal analgesic & resp. depression effects
- this confers a high safety profile clinically (better than methadone) although deaths have occurred from overdoses
- the high affinity blockade significantly limits the effect of subsequently administered opioid agonists or antagonists
- results are comparable to methadone
- can be taken on alternate days
- more expensive than methadone but may become Rx of choice
- pts on large doses of heroin may experience some withdrawal symptoms
- dose regimen:
- 8-12mg sublingually daily for 5-7 days then maintenance dose 4-32mg/d will suppress symptoms of withdrawal & reduce illicit opioid use. Dosing can be extended to every 2-3 days.
- acute overdose:
- naloxone may be helpful in improving resp. depression although improvement in mental state may be less. Doses of 5-10mg may be needed.
- leva-alpha-acetylmethadol (LAAM):
- a methadone derivative with longer half-life allowing alternate day dosing
- maybe available in Australia soon
- sustained release oral morphine (SROM):
- few studies; a trial has commenced in Australia in 2000;
- prescription heroin:
- has been available in UK since 1926 but has not been well studied.
- results might be comparable to methadone & a Swiss study in late 1990's showed impressive results
- may have a place in users refractory to other Rx
- non-pharmacologic Rx:
- examples:
- drug-free outpatient counselling
- residential rehabilitation
- self-help groups (eg. Narcotics Anonymous)
- retention is often poor& good evidence of benefit is hard to find
opioid_dependence.txt · Last modified: 2024/08/13 01:57 by gary1