Drug Abuse - Unusual Presentations

Managing drug abusers in primary care involves not only treating patients who admit to their dependency but also recognising the signals in those who are reluctant to share this information. Not infrequently, you will also be approached by temporary patients attempting to obtain drugs by deception. GPs need to be alert to the following clues:

• Temporary residents just passing through the area
• Patients with an overly familiar knowledge of the pharmacopoeia demanding analgesia for renal colic, sickle-cell crises, etc.
• Patient gives evasive answers
• Signs of heavy smoking, strange smoke smells (cannabis, cocaine, heroin)
• Acetone or glue smell on breath (solvent abuse)
• Small pupils (opiates)
• Needle tracks on arms, groin, legs, between toes; intravenous access difficult
• Abscesses and lymphadenopathy in nodes draining injection sites
• Signs of drug associated illnesses (e.g. endocarditis. AIDS, chronic viral hepatitis)

Patients may present with a variety of medical conditions but the GP may not be aware of the history of drug dependency. The following are a list of common scenarios:

• Patient found unconscious - consider narcotics, barbiturates, solvents, and benzodiazepine (see also Opiate Poisoning and Coma)
• Psychosis - consider Ecstasy, LSD, amphetamine, anabolic steroids¹
• Agitation - common with benzodiazepines
• Asthma/dyspnoea - consider opiate-induced pulmonary oedema, asthma (may follow the smoking of heroin)^2,3
• Lung abscess -may be a complication of right-sided Staphylococcal endocarditis - common in intravenous drug abusers⁴
• Fever/PUO/shivering - may be only sign of endocarditis⁴
• Shivering and headache - due to chemical/organism contamination of intravenous drug, if suspicious outline risks, offer immediate referral to secondary care - may need blood cultures, antibiotics, e.g. gentamicin.
• Hyperpyrexia - consider Ecstasy, be wary of associated myoglobinuria, DIC, renal failure
• Abscesses - if over injection site, then often of mixed organisms
• DVT - may result from injecting suspension of tablets into groin, consider acute compartment syndrome, organise a CK test⁵
• Pneumonia - Pneumococcus, haemophilus, tuberculosis, pneumocystis
• Tachyarrhythmia - in young patients consider cocaine, amphetamines, endocarditis⁶
• Jaundice - Hepatitis B, C, or D,anabolic steroids (cholestasis)
• 'Glandular fever' - may actually be HIV seroconversion illness
• Pain in a limb or back pain with fever - consider osteomyelitis
• Severe constipation - unusual in young patient, may be sign of opiate abuse
• Blindness - may be secondary to fungal or bacterial endophthalmitis with or without endocarditis, or talc or other particulate emboli⁷
• Rhinitis - consider opiate withdrawal - other features may be colic/diarrhoea, lacrimation, dilated pupils, insomnia, piloerection, myalgia, low mood (rhinitis may also be a sign of cocaine use).
• Signs of sensory or motor neuropathy - consider solvent abuse
• Infarctions - MI, stroke or TIA, spinal - suspect cocaine use⁸

The general management of substance misuse has been extensively revolutionised with the release of consensus guidelines in 2007.⁹ These guidelines take on board the NICE suite of guidance on substance misuse as well as other evidence-based studies.^{10,11,12,13,14} The guidelines cover a wide range of issues and need to be read in detail by health professionals who come into contact with people requiring care for substance misuse. Essential components include:

• The prevalence of drug misuse in the UK
• Drug-related morbidity and mortality
• The impact of drug misuse on families and communities
• Models of drug treatment
• Clinical governance principles
• Non-medical prescribing (i.e. prescribing by health professionals other than doctors or dentists)
• Confidentiality, information sharing and child protection
• Patient and carer involvement
• Assessment, planning care and treatment
• Drug testing
• General health assessment
• Psychosocial components of treatment
• Pharmacological interventions
• Assessing and responding to progress and failure to benefit
• Opioid maintenance prescribing
• Opioid detoxification
• Naltrexone for relapse prevention
• Benzodiazepines
• Stimulants
• Preventing drug-related deaths
• Alcohol misuse
• Specific clinical situations such as prisoners, pregnant patients, mental health issues and older current and ex-drug users
• Pain management
• Hospital admission and discharge