Burden, Risk Factors, and Knowledge of Non-fatal Opioid Overdose Among Injectable Drug Users: A Cross-sectional Study

Opioid overdose is a significant public health problem among injectable drug users (IDUs), with non-fatal overdoses being a strong predictor of fatal overdoses. This study aimed to evaluate the burden, risk factors, and awareness related to non-fatal overdose among IDUs in Kolkata, India.

This cross-sectional study was conducted from September 2023 to March 2025 at two opioid substitution therapy centers and two government hospitals in Kolkata. A total of 331 IDUs diagnosed with opioid use disorders participated. Data were collected through face-to-face interviews using a structured questionnaire assessing socio-demographics, substance use, overdose risk factors, and knowledge of overdose management. Descriptive statistics and regression analysis were employed.

A total of 331 IDUs were included. Among them, 73% used heroin, and 72.3% used buprenorphine. Major risk factors were sudden increases in heroin dosage (88.1%), injecting alone (83.8%), and sharing syringes (82.5%). Additionally, 24.1% reported a history of incarceration. Only 55.5% knew about calling an ambulance during an overdose, while 96.3% were aware that higher doses increase overdose risk. None were aware of naloxone use. Most participants (77.4%) expressed the need for more training on overdose management, while 88.7% feared aggression from overdose victims when administering naloxone. Attitude showed a protective trend, while knowledge and cumulative risk scores were not significantly associated with overdose in regression analysis.

The findings underscore the need for comprehensive overdose prevention programs, including naloxone distribution and training and community-based education to address knowledge gaps and reduce opioid overdose mortality among IDUs in Kolkata.