Hydromorphone and infective endocarditis risk in people who inject drugs

Takeaway

• Exposure to controlled-release hydromorphone was associated with a higher risk of infective endocarditis among people who inject drugs (PWID).

Why this matters

• Findings provide the first evidence of the possible cause of the widely increasing incidence of infective endocarditis in PWID.

Study design

• A retrospective cohort study of 60,529 PWID (2006-2015).
• In the population-level analysis (n=32576), patients living in regions with high (≥25%) and low (≤15%) hydromorphone prescription rates were matched 1:1 and their frequency of infective endocarditis was compared.    
• In the patient-level analysis (n=7768), people who filled a hydromorphone prescription were matched (1:1) with those who had filled prescriptions for other opioids and their frequency of infective endocarditis was compared.
• Funding: Ontario Ministry of Health and Long-Term Care and others.

Key results

• Of 60,529 hospitalised PWID, 733 (1.2%; 95% CI, 1.1-1.3%) had infective endocarditis.
• In the population-level analysis, a higher proportion of hospital admissions for infective endocarditis was reported in regions with high hydromorphone vs low hydromorphone use (adjusted odds ratio [aOR], 2.2; 95% CI, 1.8-2.8; P<.0001).
• In the patient-level analysis, the frequency of infective endocarditis was higher among patients who received prescriptions for hydromorphone vs those who received non-hydromorphone opioids (aOR, 2.5; 95% CI, 1.8-3.7; P<.0001).
• The risk for infective endocarditis was higher among PWIDs who were prescribed controlled-release hydromorphone compared with those who prescribed other opioids (aOR, 3.3; 95% CI, 2.1-5.6; P<.0001).
• Immediate-release hydromorphone was not associated with an increased risk for infective endocarditis (aOR, 1.7; 95% CI, 0.9-3.6; P=.072).

Limitations

• Retrospective design.