6. Heroin

As an analgesic heroin is safe, effective and has a wide safety margin. However, it is perceived by many as a 'horror drug'. The situation demonstrates the powerful influence of policies or legal status of a drug on the lives of those who choose to use the substance unlawfully.

Heroin is a semi-synthetic opiate derived from morphine. It is produced in minimal amounts legally and street heroin is produced in illicit laboratories. The chemical is a white crystalline powder, soluble in water. Coloured preparations reflect different contaminants present.

The drug is most commonly administered by injection (IV or IM) but it is also active if smoked. While the drug can be used orally it is more often used parenterally because this is a far more cost effective means of achieving the desired psychoactive effects.

The onset of action is rapid and the duration of action is approximately 3-4 hours. The immediate effect or 'rush' after an IV dose is related to the high fat solubility of the drug and thus its rapid entry into the brain.

As heroin is not legally available in Australia, illegal users obtain supplies of the drug on the street. This results in the dosage being:

• of variable amount; and
• contaminated by a variety of diluents of varying quality and safety.

Most users inject their dose using a number of solvents for the powder they purchase. Acidifying agents are used to facilitate dissolving the drug and these in their own right may produce complications (eg fungal contamination of lemon juice). Users inject intermittently and may pass from recreational use (1 x week or less) to a major habit where doses costing up to $1000 day are used in 3-4 injections.

It is apparent that treating an individual who shoots up four times a day with heroin would prove very difficult if each dose had to be supervised. Many illicit users are unable to obtain regular doses every day and will substitute heroin with other CNS depressants, typically benzodiazepines.

Apart from the risk of overdose which is a direct CNS effect of the drug, most complications of heroin use relate to the injection of contaminated material, or the use of non-sterile injecting equipment.

• Acute heroin reaction – a syndrome with acute onset and signs of cardiovascular collapse; may prove fatal.
• Septic complications (often resulting from the use of non-sterile injecting equipment):
  
  • septicemia
    
  • bacterial endocarditis
    
  • skin abscesses
    
  • infective emboli
    
  • ophthalmitis – fungal
    
  • viral infections – hepatitis B
    
  • hepatitis C
    
  • HIV.
    
• Neurological complications:
  • infections
    
  • embolic lesions
    
  • trauma to nerves from direct injection.
    
• Sexual transmission of HIV, hepatitis B.
  

Dependence, both physical and psychological, results from regular use of the drug and withdrawal will develop within 12 hours of ceasing regular usage. Maximal withdrawal symptoms are experienced between 36 and 72 hours and symptoms consist of:

• chills and shivering
• excessive sweating
  
• gooseflesh is prominent (cold turkey)
• irritability
  
• insomnia
• loss of appetite
  
• rhinorrhoea and lacrimation
• muscle aches and cramps, restlessness
  
• diarrhoea
• yawning.

Management of heroin dependence is complex. A number of alternatives are available to those who are opioid-dependent. Treatment options include methadone substitution, detoxification in a hospital or approved detoxification centre, supervised outpatient detoxification, drug-free therapeutic community programs, rehabilitation in a residential centre, individual or family counselling and self-help groups.

While drug-free treatments attract fewer patients than methadone maintenance, have lower rates of retention in treatment, and lower rates of successful graduation to a sustained drug-free lifestyle, they have been shown to be effective in reducing the frequency of injecting drug use. The natural history of opiate dependence indicates that many do grow through their period of dependence irrespective of treatments offered. Each approach aids some patients but by no means all.

The morbidity of heroin users is significantly higher than that of their non-drug using peers. This reflects the severity of many of the complications they experience, including those related to their drug-seeking lifestyle, eg nutritional deficits, violence.

* These effects should not usually occur if the appropriate dose of methadone has been prescribed. However, if any of these effects occur, they should be reported immediately and dose and frequency of administration monitored or adjusted.

Methadone, when administered in pure and regular doses as part of a treatment program, should not have any severe long-term effects on an individual's health.

Possible long-term effects:

• weight increase, usually due to fluid retention or change in diet
• tooth decay, due to reduction in amount of saliva produced (is often present prior to participation in methadone program)
  
• may lead to impotence or delayed ejaculation in some men
• loss of libido has been reported by some women
  
• amenorrhoea
• disrupted menstrual cycles
  
• reduced fertility
• methadone can be particularly harmful to people with kidney and liver diseases.

These effects are often emphasised by the opiate-dependent and their suppliers to avoid treatment.

MIXING DRUGS CAN BE DANGEROUS

Using other drugs with methadone can be dangerous. This includes alcohol, tranquillisers and cannabis. While some drugs reduce or change the effects of methadone, methadone itself can alter the effectiveness of other drugs, or produce unexpected side effects.

It is very important that people inform their doctor or dentist of their participation in a methadone maintenance program to ensure that they are not prescribed anything which could affect the treatment, and so that other medical procedures (eg administration of anaesthetics) are safe.

In establishing an effective methadone program, it is appropriate to have a clear view of what the methadone is being used for. Guidelines for achieving success should include:

• establishing the goals and objectives of the program
• educating staff on the goals and objectives and reasons for them
  
• providing information to patients on the goals of the program
• establishing a working system directed to achieving the goals
  
• adhering to unit policy.

This list does not suggest that policies may vary from unit to unit and this is indeed the case. Perhaps the most common use of methadone is in the form of a long-term maintenance program in which patients receive a once-daily doses of methadone over a period of months or, in many cases, years. Urine testing is carried out in almost all programs and it is appropriate for patients to be challenged if heroin use continues. Exactly what steps should be taken in a patient who persistently uses heroin remains debatable. The approval of a State health authority is required both for doctors to prescribe methadone and for a drug-dependent person to receive it.

Methadone maintenance is a complicated treatment for a complex group of patients. Individuals should not embark on such programs without very clear guidelines and without links to a major unit that can provide support should difficulties arise.

The Human Immunodeficiency Virus (HIV) has three main modes of transmission. It can be transmitted through the exchange of HIV-infected body fluids during unprotected sex; through the use of HIV-contaminated injecting equipment; and may be passed on from mother to child during pregnancy or birth, and possibly via breast milk during feeding.

Injecting drug users are potentially at risk for transmission of HIV through sexual contact or use of non-sterile injecting equipment. As there is no cure for HIV/AIDS, the only way to curb its rapid spread is by eliminating or modifying the risk behaviours involved in its transmission.

For injecting drug users changes may include abstinence, or if this is not feasible, either changing the route of administration of the drug (eg oral ingestion or smoking), or undertaking safer injecting practices, namely, not sharing injecting equipment or, if sharing, properly cleaning the equipment by either sterilising or rinsing with bleach.

Medical practitioners and other health workers to should alert injecting drug users to the risks of HIV transmission and provide them with information about safe sexual and injecting behaviour. Appropriate information may include:

• warning about the risks of needle sharing
• needle and syringe cleaning techniques
  
• the availability of clean needles and syringes or needle exchange programs in the area
• safer sexual practices
  
• the availability of free condoms.

New users and irregular users are also a group which are at high risk of contracting the HIV infection through the use of contaminated injecting equipment. For new users this occurs because they are usually initiated with the use of an experienced user's injecting equipment, while for irregular users their drug use is often unplanned and thus they may share needles because they do not possess the necessary equipment.

Methadone maintenance programs have been found to be effective in reducing the frequency of injecting and the incidence of needle sharing. They are also effective dissemination points for information about HIV/AIDS, and for users who may be infected with HIV they provide vital contact with the health system.