Estimated numbers of people prescribed opioid substitution therapy in Scotland
Scottish Public Health Observatory update 2025/26 Q1: 12 months to 30 June 2025

About this release

This release by Public Health Scotland (PHS) provides quarterly estimates of the number of people prescribed Opioid Substitution Therapy (OST) medications (for example, methadone) for the treatment of opioid dependence, by area of residence. These estimates relate to the 12-month period to 30 June 2025 (the end of 2025/26 Q1).

These estimates were previously published on the Drugs topic pages of the Scottish Public Health Observatory (ScotPHO) website. Updates to ScotPHO are currently on hold pending a review of the future role of the website. Future updates of these estimates will be released as part of the RADAR Quarterly Report.

Main points

In the 12-month period ending 30 June 2025 (the end of 2025/26 Q1):

Based on data from the Prescribing Information System (PIS) only (Tab1 Q OST Estimates (PIS)):

• OST was prescribed to an estimated minimum of 26,312 people in Scotland. This was a small decrease compared to the 2024/25 Q4 estimate (26,567) and the lowest estimate in the available time series (2024/25 Q2 to 2025/26 Q1).
• The local authorities where the highest estimated numbers of people prescribed OST lived were Glasgow City (5,373; 20%), City of Edinburgh (2,616; 10%), and Fife (1,693; 6%).
• The NHS Board areas where the highest estimated numbers of people prescribed OST lived (based on figures for their constituent local authorities) were Greater Glasgow & Clyde (8,060; 31%), Lothian (4,069; 15%) and Lanarkshire (2,959; 11%).

Based on combined data from the Prescribing Information System (PIS) and the Hospital Medicines Utilisation Database (HMUD) (Tab2 Q Combined OST Estimates):

• OST (inclusive of injectable buprenorphine prescribing) was prescribed to an estimated minimum of 27,696 people in Scotland. This was a small decrease compared to the 2024/25 Q4 estimate (28,015).
• The NHS Board areas where the highest estimated numbers of people prescribed OST (inclusive of injectable buprenorphine prescribing) lived were Greater Glasgow & Clyde (8,145; 29%), Lothian (4,376; 16%) and Lanarkshire (2,961; 11%).

Background

These estimates describe the number of people in Scotland who were prescribed Opioid Substitution Therapy (OST) medications in a given 12-month (rolling) period, with data updated each quarter. The most recent update, covering the four financial year quarters up to 2025/26 Q1, shows estimates of the number of people prescribed OST medications from 1 July 2024 to 30 June 2025. The previous estimate (2024/25 Q4) is available at ScotPHO and represents the four financial year quarters from 1 April 2024 to 31 March 2025. 

These estimates relate to the dispensing of methadone hydrochloride, buprenorphine, buprenorphine & naloxone and long-acting buprenorphine (including Buvidal© slow-release formulations) for the treatment of opioid dependence from legacy British National Formulary (BNF) subsection 04.10.03. Lofexidine hydrochloride and naltrexone hydrochloride (both primarily used for the management of opioid withdrawal) are not included. Please see the Drugs Included tab of the workbook for further details of medications included in this analysis. 

These figures are based on combined data from Prescribing Information System (PIS) and Hospital Medicines Utilisation Database (HMUD) for a rolling 12-month period and represent the minimum number of individuals prescribed OST medications in community settings and via hospital supply. Issues of accuracy or completeness relevant to each data source are described below.

Prescribing Information System (PIS) data

• The Quarterly OST Patient Estimates shown in Tab1 Q OST Estimates (PIS) are based on patients’ local authority of residence and include totals for groups of local authorities which correspond to NHS Board areas. These estimates are based on the number of unique Community Health Index (CHI) numbers captured from named community prescriptions for relevant medications at any time within 12 months of each financial year quarter. Issues associated with CHI capture for OST prescriptions which mean that it is challenging to provide a robust count of the number of people prescribed these medications. Generally, patient numbers and characteristics are only provided when CHI completeness is 85-90% or higher. National completeness is currently below this threshold (82.7% in 2024/25) and data completeness remains variable at NHS Board level. Therefore, estimates for specific geographies should be interpreted with reference to the CHI capture information shown in the annual OST estimates (Opioid Substitution Therapy).

Hospital Medicines Utilisation Database (HMUD) data

• Tab2 Q Combined OST Estimates provide details of the number of patients prescribed methadone, oral buprenorphine, and injectable buprenorphine (inclusive of PIS and HMUD data) by NHS Board of residence for 2024/25 Q1 to 2024/25 Q4. HMUD contains details of long-acting buprenorphine treatments administered in community settings which are prescribed via hospital stock order forms. As HMUD does not include patient details, it is not possible to produce patient estimates in the same way as for PIS. Following consultation with specialist Pharmacists, it has been agreed that the average number of 28-day injectable buprenorphine formulations ordered per month (based on quarterly data) can be used to estimate the number of patients to whom treatment is delivered in each NHS Board. HMUD data are available at NHS Board level only and estimates are therefore not shown by local authority of residence.

The variable quality of prescription data and use of proxy measures for stock order data means that these figures, and comparisons over time, should be treated with caution. These figures are described as 'estimates' or 'minimum numbers' due to the reasons outlined above, and it is likely that the true number of people receiving OST may be higher. Use of a 12-month rolling timeframe means that this estimate reflects changes over a lengthy period of time. This helps to limit the impact of variations in data completeness but also means that changes in OST prescribing may not be reflected in a timely manner. Due to the public interest in OST prescribing, these statistics are published as management information.

Further information

These estimates were previously published on the drugs topic pages of the Scottish Public Health Observatory (ScotPHO) website. Updates to ScotPHO are currently on hold pending a review of the future role of the website. Future updates of these estimates will be released as part of the RADAR quarterly report.