Background In 2020, Drug Related Deaths (DRD) in the United Kingdom (UK) reached the highest rate in over 25 years, with opioid related deaths doubling in the years from 2012 to 2015. Treatment systems are increasingly required to be innovative to engage the most vulnerable at risk from DRD. Heroin Assisted Treatment (HAT) is an alternative treatment modality for people for whom more traditional forms of Opioid Substitution Therapy (OST), such as methadone and buprenorphine, are ineffective. Middlesbrough, a town in the North-East England, was home to the first service in the UK to implement HAT outside of a clinical trial setting.

Methods Qualitative in-depth interviews with 17 health care providers (HCP) involved in the delivery or implementation of HAT were undertaken remotely. Interviews were audio recorded and thematically analysed.

Results HCP navigated multiple layers of constraint during HAT implementation and delivery. We explore this in relation to three themes: 1) Negotiating risk and safety within treatment. 2) More than a prescription: care beyond diamorphine 3) Internal and external delivery barriers and impact on treatment acceptability, identity and longevity.

Negotiating and managing risks of poly substance use was a complex task for HCP. Benefits regarding access to holistic care, improved therapeutic and social relationships were recognised by HCP. The rigorous delivery schedule was the biggest barrier to engagement. Outside the treatment room, socio-structural barriers and short-term commissioning cycles posed additional challenges to the sustainability and delivery of the intervention.

Conclusion Delivering HAT from the perspective of HCP is an effective method of engaging a population of marginalised people who use drugs (PWUD) with treatment services, and offers benefits over and above the provision of diamorphine. Recommendations to improve service delivery and roll out of HAT across the UK are suggested.