Errors in prescribing, supervised or non-supervised dispensing, and monitoring and communication, were responsible for patient safety incidents in opioid substitution treatment, a study from England and Wales has shown.

Data on patient safety incidents involving patients receiving either methadone or buprenorphine treatment in community services between 2005 and 2015 were extracted from the National Reporting and Learning System.

This is a national database of patient safety incident reports maintained by the NHS in England and Wales.

Eligible reports were manually reviewed to check that they fitted study criteria, and the resulting study population comprised 2,284 safety incident reports.

Methadone was the most commonly reported drug (n = 1,862; 82%) followed by buprenorphine (n = 394; 17%) and buprenorphine and naloxone in combination (28; 1%).

Most incident reports from opioid substitution treatment came from failure in one of four processes of care delivery: non-supervised dispensing (n = 1,544) examples included dispensing incorrect doses and dispensing to the wrong patient; supervised dispensing (n = 318) e.g. incorrect dose, wrong patient and failure to supervise consumption; monitoring and communication (n = 248) e.g. failing to stop dispensing when appropriate; and prescribing opioid substitution treatment (n = 151) e.g. incomplete or inaccurate prescriptions and prescriptions for the wrong dose.

For incidents associated with harm, prescribing opioid substitution had the highest proportion (14 of 151; 9%), followed by monitoring and communication-related incidents (22 of 284; 8%), and failures with supervised dispensing (24 of 318; 8%). Non-supervised dispensing had the lowest proportion resulting in harm (57 of 1,544; 4%).

Overall, 94% (n = 2,155) of incidents resulted in no harm, while 6% (n = 129) caused low or moderate harm to the patient. There were no incidents resulting in severe harm or death.

Contributory factors (categorised as staff; organisational; patient; medication storage and packaging; or information technology) were identified in 75% of incidents with 40% involving more than one factor.

Opioid substitution therapy is an effective harm reduction strategy in the management of opioid dependence and reduces illicit drug use and associated morbidity. Substitution therapy is widespread and evaluating the safety of treatment programmes is vital.

Based on their findings the authors conclude that priority areas to promote safe opioid substitution include prescriber education, implementing and strengthening electronic prescribing systems, strengthening dispensing and monitoring systems and developing specific procedural and educational interventions for pharmacy staff.

Dr Jez Thompson