Substance misuse - Minimising the risks of injecting

Dr Meg Thomas sets out health promotion strategies to help patients who are drug users.

Cellulitis may result from overuse of injection sites
Cellulitis may result from overuse of injection sites

Intravenous drug (IVD) users have a mortality rate up to 24 times that of the general population and suffer significant morbidity.1

The health of users can be greatly improved by treatment, including substitute prescribing.1 However, substitute prescribing is beyond the scope of this article, which focuses on health promotion.

Advice is best received when given in a non-judgmental and empathetic way.2 Motivational approaches have a particularly sound evidence base.3

Harm minimisation advice
Give the initial message that there is no completely safe way of injecting drugs, and that patients can greatly reduce the risk of overdose and infection by not injecting.

Instead, heroin can be smoked, sniffed or injected rectally (no needle). Cocaine can be sniffed or smoked as crack and amphetamines can be swallowed or sniffed.

Give advice to those who are going to continue to inject. Around 25 per cent of IVD users still share injecting equipment ('works') and more than half are infected with hepatitis C.4

Back up advice with written information. The Safer Injecting Handbook is available free from many drug services and online at Also recommend patients use the local needle exchange service.

Give information to reduce blood-borne virus (BBV) transmission. Advise users to avoid sharing all works, including needles, syringes, spoons, water and filters. Many users do not see sharing with a regular partner as sharing.

Provide hepatitis B (HBV) immunisation for IVD users and household contacts, particularly sexual partners and children, as an accelerated schedule.5 This should not be dependent on prior BBV screening.

Also provide hepatitis A vaccination as a separate vaccine, because greater protection against hepatitis A is offered compared with the combined vaccine.

Advise patients how to avoid contamination with BBVs or bacteria. Give the message that anything used in the injecting process that is not sterile may be contaminated by bacteria, including tap water. Explain that works and injection sites should be clean.

Heroin is prepared by dissolving it in acid and water and warming it in a spoon. A newly-opened ampoule of sterile water for injection should be used.

Vein damage
Explain that the inside of the elbow is the least dangerous place to inject and that sites should be rotated. Check injection sites as part of the con- sultation.

Unsafe injecting sites include the lower arm veins (this practice limits emergency venous access) and the veins in the hands and feet (ischaemic risk).

Give information on high-risk injecting sites. These include the backs of the legs and the femoral vein (risk of DVT, arterial bleeding, ischaemia or severe nerve pain).

Once users have found the femoral vein they tend to use it over and over again. This has the added risk of sinus formation and severe infection. Injecting into the neck has obvious risks, injecting the breasts risks mastitis and injecting the penis may result in priapism.

Cocaine is a local anaesthetic, which is disinhibiting and, because it is often injected frequently, risks damage to veins.

Speedballing (injecting a crack/heroin mix) and temazepam are very damaging to veins.

Explain that injecting acids can also cause vein damage. Tell users to use as little acid as possible, and to use citric acid, because other acids such as lemon juice and vinegar can cause lead to candida infection, endophthalmitis and subsequent blindness. Citric acid sachets are available at needle exchanges.

Give advice on avoiding and dealing with overdose. Warn patients never to inject alone or in the bath. Advise patients to inject half of the barrel initially and wait until they get the first rush: 'If it knocks you out, injecting more will at best be a waste and could kill you'.

Inform users of the dangers of poly-drug use. Most deaths are caused by combinations of sedatives such as alcohol, benzo-diazepines, methadone and heroin. These drugs can work together synergistically.

Explain that many overdoses are due to loss of tolerance. People who have been 'clean' for a while (in rehab or prison), but then go back to opiates are very vulnerable. Take-home doses of naloxone and training in resuscitation for IVD users saves lives, and are cost-effective and safe.6

Sexual health
HIV and HBV are spread by sexual transmission. The risk of sexual transmission of HCV is negligible.7

Give advice to limit the number of sexual partners and to use condoms as well as effective contraception such as a long- acting reversible contraceptive.

Advise that HBV and HIV can be transmitted through body fluids such as saliva.

Be sensitive to the fact that some drug misusing women will be sex working.

Children of drug users
Advise parents to keep take-home doses of methadone under lock and key, and give information on the danger of methadone to opiate naive individuals.8

Parental drug use is not automatically correlated with poor parenting. National guidelines call for a comprehensive assessment of drug-misusing parents.1

When to seek urgent help
Give advice on when to seek urgent medical advice, such as if there is calf swelling, injection sites that are painful, hot and/or red or if there is general ill health, especially where there is fever.

  • Dr Thomas is a GP in Swindon, Wiltshire

Further information
I would encourage GPs who want to learn more to do the RCGP Part 1 Certificate in Substance Misuse. See


1. National Treatment Agency for Substance Misuse. Drug Misuse and Dependence: UK Guidelines on Clinical Management. October 2007.

2. National Treatment Agency for Substance Misuse. Engaging and retaining clients in drug treatment. May 2004.

3. NICE. CG51 Drug Misuse and Psychosocial Interventions. London, NICE, 2007.

4. Health Protection Agency. Shooting Up - Infections among injecting drug users in the United Kingdom, 2008. Update: October 2009.

5. RCGP. Guidelines for Hepatitis A and B vaccination of drug users in primary care and criteria for audit. London, RCGP, 2005.

6. Dettmer K, Saunders B, Strang J. Take home naloxone and the prevention of deaths from opiate overdose: two pilot schemes. BMJ 2001; 322: 895-6.

7. Vandelli C, Renzo F, Romano L et al. Lack of evidence of sexual transmission of hepatitis C among monogamous couples: results of a 10-year prospective follow-up study. Am J Gastroenterol 2004; 99(5): 855-9.

8. Bloor R, McAuley R, Smalldridge N. Safe storage of methadone in the home - an audit of the effectiveness of safety information giving. Harm Reduct J 2005; 2: 9.

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