17. Important issues

Infection with the Human Immunodeficiency Virus (HIV) may result in a wide range of complications including Acquired Immune Deficiency Syndrome (AIDS). HIV is transmitted by exchange of bodily fluids eg during sexual contact, injecting drug use, pregnancy, childbirth, or breastfeeding. HIV transmission among drug users occurs through each of these mechanisms, but the most common is through sharing injection equipment.

In most western countries during the early years of the epidemic, homosexual/bisexual males were the highest risk group, whereas in recent years cases involving injecting drug users have become more common in North America and Western Europe. Subsequently, the incidence of AIDS has increased among children and non-drug using heterosexuals.

In January 1993 in Australia, 7.7% of all people diagnosed with HIV and 3.9% of people living with AIDS were identified as injecting drug users. While these figures appear relatively low compared with some western countries, eg Italy or Spain, where injecting drug users constitute the majority of HIV/AIDS cases, HIV has the potential to spread rapidly among the population of injecting drug users in Australia unless precautions are taken.

HIV infection can spread rapidly among drug users. The development of AIDS takes on average 10-11 years from the time of infection. In countries where substantial proportions of drug users have become infected with HIV, the majority of children with AIDS have been found to have drug-using parents. Injecting drug users are regarded as the most likely conduit for HIV infection to reach the general community.

Alcohol intoxication and other disinhibiting drugs may also contribute to the risk of HIV infection as the disinhibition resulting from the use of these drugs may increase the likelihood of unsafe sexual practices.

Medical practitioners have an important role to play in the community's response to HIV infection. As infection with HIV and the resulting complications become more common in Australia, treatment will increasingly require involvement of general practitioners. Medical practitioners also have an important role in reinforcing educational efforts to reduce behavioural patterns associated with HIV transmission.

In most cases of HIV infection there are no symptoms or signs within the first few months or years. However, about half of the individuals develop non-specific symptoms from 2-6 weeks following infection. The illness resembles an attack of infectious mononucleosis. Symptoms include high temperature, muscle aches and pains, rashes, headaches and lassitude. These symptoms usually last for several days and resolve spontaneously. This cluster of symptoms is referred to as the Group I stage of HIV infection.

The development of antibodies to HIV (Group 2) may take up to 12 weeks; for about 1% of people it can take longer than 12 weeks. People with HIV (Group 2) are, by definition, asymptomatic although non-specific symptoms are not uncommon.

Group 3 involves persistent generalised lymphadenopathy in the absence of a concurrent illness or condition other than HIV infection to explain the findings (sometimes known as AIDS-related conditions).

Group 4 includes the most advanced stage of HIV infection and is usually known as AIDS. This is constituted by the presence of an opportunistic infection and/or neoplasm in the presence of severe immunodeficiency. Severe diarrhoea, weight loss and other major symptoms are often present. Specific neurological impairment or severe wasting syndromes are also classified as Group 4.

The Albion Street Centre in Sydney is currently revising and updating The AIDS manual, a comprehensive reference on the human immunodeficiency virus. The third edition, published by McLennan and Petty, is perhaps the most authoritative reference text on AIDS produced in this country, and will be available late 1993.

The AIDS manual provides up-to-date information on statistical trends in Australia and overseas, the changing nature and treatment of the disease, counselling, education and social, occupational and legal issues. The manual provides current information on the effects of AIDS on particular groups such as injecting drug users and haemophiliacs, children and women of child-bearing age. The manual includes useful diagrams, clinical photographs, supplementary reading material and an index.

The management of chronic pain can be one of the most difficult tasks in medical practice.

• Attention should be directed to the underlying factors which exacerbate the pain or decrease tolerance to it.
• Many doctors are fearful of creating addicts and provide too little analgesia even for patients with terminal conditions.
  
• The irrational prescribing of patient opioid analgesics administered by injection for chronic low grade benign pain is equally difficult to defend.
• Oral administration is always preferred to parenteral routes for the management of chronic pain.
  
• Simple analgesics such as aspirin or paracetamol should be tried first. If this does not provide adequate relief, combinations of either aspirin or paracetamol with codeine should be tried next.
  
• If more potent analgesia is required, orally absorbed, long-acting opioids such as oxycodone should be prescribed.
• Morphine can be given orally with satisfactory results, but the dose required might be 3-6 times the parenteral dose because of variable absorption and hepatic metabolism.
  
• The use of adjuvant drugs including NSAIDs and tricyclic antidepressants is very important.
• Pain in inflammatory conditions should be controlled by NSAIDs without requiring opioids. It is important to appreciate that the very satisfactory analgesia produced by opioids in acute pain is not necessarily achieved by opioids when used for other pharmacological treatments.
  
• Increasing the dose merely increases the risk of side effects including drug dependence.
  
• The use of a range of behavioural approaches is as important as pharmacological treatment in chronic pain management.
• Techniques include relaxation therapy, trans-electronic nerve stimulation (TENS) and self-help chronic pain groups.
  
• Pain clinics or pain specialists are now available in major centres and these will have available a range of similar psychologically based and other treatments. In cases of prolonged or intractable pain, consideration should be given to referral to such clinics.