HealthDay News — Exposure to controlled-release hydromorphone, an opioid that can be abused through crushing and injection, is associated with an increased risk for infective endocarditis among people who inject drugs, according to a study published online Jan. 22 in The Lancet Infectious Diseases.
Michael Silverman, M.D., from Western University in London, Ontario, Canada, and colleagues measured the incidence of infective endocarditis among 60,529 patients with evidence of injection drug use in a cohort assembled using health administrative databases in Canada. In a population-level exposure analysis (32,576 matched patients), the authors examined infective endocarditis incidence relative to regional rates (high, low) of hydromorphone prescription. In a patient-level exposure analysis (3,884 matched patients), the authors compared the frequency of infective endocarditis among patients who filled prescriptions for controlled-release and immediate-release hydromorphone versus other opioids.
The researchers found that 1.2 percent of patients in the retrospective cohort had infective endocarditis. In the population-level analysis, the frequency of admissions for infective endocarditis was 1.6 percent in regions with high hydromorphone prescription rates and 0.7 percent in regions with low hydromorphone prescription rates (adjusted odds ratio [aOR], 2.2; 95 percent confidence interval [CI], 1.8 to 2.8; P < 0.0001). In the patient-level analysis, the frequency of infective endocarditis was 2.8 percent in patients who filled prescriptions for hydromorphone compared with 1.1 percent in patients who had filled prescriptions for nonhydromorphone opioids (aOR, 2.5; 95 percent CI, 1.8 to 3.7; P < 0.0001). The frequency of infective endocarditis among those who filled prescriptions for hydromorphone compared with those who filled prescriptions for other opioids was significantly higher for the controlled-release form (3.9 versus 1.1 percent; aOR, 3.3; 95 percent CI, 2.1 to 5.6; P < 0.0001) but not for the immediate-release form (1.8 versus 1.1 percent; aOR, 1.7; 95 percent CI, 0.9 to 3.6; P = 0.072) of hydromorphone.
“There’s been a global increase in infectious diseases among persons who inject drugs and our research suggests that controlled-release prescription opioids may be a major culprit,” Silverman said in a statement. “We now have evidence that suggests the injection of controlled-release hydromorphone is increasing the spread of HIV, hepatitis C, and endocarditis in Canada.”