July 13, 2010

Q&A: Intravenous Drug Use Complications

People who inject drugs (PWID) are vulnerable to a wide range of viral and bacterial infections. These infections can result in high levels of illness and in death.

This article is for Medical Students & Professionals
This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find more useful one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
Intravenous drug misuse (shooting up)
MCQ exam: clinical scenario
MCQ exam: answer
MCQ exam: explanation

Intravenous drug misuse (shooting up)

Intravenous drug (IVD) use (also IVDU) is clearly endemic in many societies and all primary care physicians will come into contact with users.

All illicit substances have risks. Use of the IV route is the greatest. IVD use causes a whole host of complications affecting a variety of different systems in the body. IVD users have a mortality risk up to 24 times that of the general population.

The main risks of IVD use are dependency, damage to veins, infection and overdose.

With regard to infections, illicit drugs are not manufactured in sterile conditions. This leaves users vulnerable to pathogens, even when injection technique is perfect. The following problems often arise: abscesses; cellulitis; right-sided endocarditis (usually Staphylococcus aureus); septicaemia; tetanus and botulism. Botulism presents as a descending paralysis and can be fatal. Its classic 'four Ds' symptoms comprise diplopia, dysphagia, dysarthria and dysphonia.

MCQ exam: clinical scenario

Septic pulmonary embolism in an intravenous drug abuser is likely to be secondary to:

a) P carinii
b) Nocardia spp
c) M avium-intracellulare
d) klebsiella
e) Pseudomonas aeruginosa

MCQ questions & answers on medicalnotes.info

MCQ exam: answer

The correct answer is E.
Pseudomonas aeruginosa is most commonly involved in septic pulmonary embolism among IV drug abusers.

MCQ exam: explanation

In pulmonary complications of intravenous drug abuse, septic pulmonary emboli are the most common complication, followed by community-acquired pneumonia and mycobacterium tuberculosis infection.

Most pulmonary infections are community acquired episodes of pneumonia caused by common respiratory pathogens.

In one series of febrile IVDUs, pneumonia was the most common cause of fever. In a second series, pneumonia was second only to cellulitis as a cause of fever.
  • The usual pathogens in bacterial pneumonia include Streptococcus pneumonia, oral anaerobes, S.aureus or P. aeruginosa. Lung abscesses may arise from aspiration pneumonia, necrotizing pneumonitis or septic emboli. Pulmonary tuberculosis is a major problem even in non-HIV-1-infected drug abusers
  • Streptococcus pyogenes appears to have become an uncommon cause of pneumonia
Catheter infection with S aureus, P aeruginosa, or Candida species can lead to septic pulmonary embolism, as can intravenous drug abuse.

1). Public Health England. Shooting up. Infections among injecting drug users in the UK October 2008 (updated October 2009).
2). GOV.uk: People who inject drugs: infection risks, guidance and data. Available online: https://www.gov.uk/guidance/people-who-inject-drugs-infection-risks-guidance-and-data

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