Pharmacy’s role in harm reduction in individuals with substance use disorder

Introduction

Substance use disorder (SUD) — also known as substance dependency — is used to describe the condition suffered by people who misuse substances such as alcohol, illicit substances or prescribed medicines. SUD carries a high risk of overdose, especially in the context of the ever-changing drug market, such as the advent of new psychoactive substances (NPS) and ‘legal highs’, which have evolved to avoid regulatory controls^​1,2​, as well as contamination with potent substances such as nitazenes, medetomidine and xylazine^​1,3,4​.

In 2024, the Scottish drug-related death (DRD) rate was 2.8 times that of England and Northern Ireland, and 1.9 times the rate in Wales^​5​. The most recent National Records of Scotland figures show that 1,017 people in Scotland died of a DRD in 2024^​5​. England and Wales recorded at least 3,736 deaths related to drug misuse in 2024, which has doubled since 2012^​6​. In 2022, 47.1% of DRDs in England and Wales involved opioids^​6​.

Harm reduction approaches in substance use are pragmatic activities based upon an acceptance that the provision of evidence-based efforts to minimise the negative effects and outcomes from substance use, while not preventing or promoting the problematic health behaviour itself, promotes improved health outcomes for individuals^​7–9​. This can come in many forms — for example, by providing health education to raise overdose awareness, naloxone provision, injecting equipment provision (IEP) and blood-borne virus (BBV) testing.

Pharmacy plays an important role in the provision of harm reduction to people at risk within their own communities, particularly in deprived communities where harms are felt most^​10​. In addition, pharmacy teams can counsel on the use of naloxone and support patients not known to alcohol and drug services who might access the pharmacy for IEP or advice. 

This article will provide an overview of different harm reduction strategies and highlight the role of pharmacy in reducing drug-related harm in individuals with SUD.

Principles of harm reduction associated with substance use

The rapid spread of HIV infection among people who injected drugs in the 1980s led to the pragmatic introduction and expansion of several previously existing harm reduction approaches (e.g. IEP)^​11​. These approaches were further expanded as pressure from drug use-related harms increased in the 2010s and continue to evolve today, such as the growing popularisation of injectable NPS — particularly synthetic analogues of cocaine and stimulants — and the introduction of synthetic opioid agents into the drug market^{​1,12,13​}.

Harm reduction seeks to prevent avoidable damage to the body, mind and social framework to keep an individual who uses substances as healthy as possible, for as long as possible, while efforts are made to support and encourage engagement with less risky behaviours and, ultimately, resolve the problematic behaviours through care and treatment as part of a recovery journey from substances^​14​. 

Aside from the clear humanitarian justifications for harm reduction approaches in the care of individuals, these are also often shown to be cost-effective, or even cost-saving, to healthcare systems — more so when wider societal benefits and avoidance of future care costs following preventable harms are considered^​15,16​. 

An argument often mooted against harm reduction is that removing risk and consequences may drive compensatory increases in drug use behaviours^​17​. In the case of addiction, it is important to note that a clear diagnostic criterion for the mental disorder is the persistence of use despite clear and overt negative outcomes. Therefore, risk and consequences are not effective barriers to ongoing or escalating drug use^​18​.

Future programmes, such as drug testing, drug checking or safe inhalation pipe introduction, may further aid harm reduction options within pharmacy^​19,20​. 

New substance trends and emerging concerns

Across the UK, there is an evolving landscape in substances that are being used by the population. Polypharmacy is recognised as a major risk factor in the incidence of DRD. National Records of Scotland data show that in over 80% of all drug deaths recorded in 2024, more than one substance was implicated^​5​. Office for National Statistics (ONS) figures for England and Wales demonstrate that polypharmacy was present in over 50% of DRDs in 2024^​6​.

There has also been a notable change in the substances presenting in drug death toxicology reports, data collection, as well as drug checking and testing services^​21​. Changes in both the presence of more potent synthetic versions of opioids (e.g. nitazenes) and benzodiazepines, as well as in the substances that people are choosing to use, such as the increase in use of gabapentinoids, ketamine and cocaine have also been observed^{​5,22,23​}. 

The emergence of potent synthetic opioids, such as nitazenes, orphines, fentanyl analogues and non-prescribed benzodiazepines, such as etizolam and bromazolam, is of significant concern. These substances are often unknowingly sold in place of, or contaminate, “traditional” street drugs. The uncertain and unsafe supply of these substances can result in a significant risk of harm or death as people may not know what drug or the quantity they are taking^​22​.  

ONS figures show that in 2024, cocaine-related deaths increased by 14.4% in England and Wales compared with the previous year^​6​. National Records of Scotland figures show that in 2024, cocaine was implicated in 47% of DRDs compared with 6% in 2008^​5,22​. There has been evidence of increased use of injected cocaine. According to the results of a study published in 2024, the incidence of injection of powdered cocaine in Scotland rose from 9% in 2010 (n=217) to 60% in 2022/2023 (n=761). Owing to the shorter duration of action of cocaine, frequency of injection can increase, with the associated increase in the risk of BBV transmission, such as the identified link between cocaine injection and the HIV outbreak in NHS Greater Glasgow and Clyde (GGC) in 2015^​24​.

Within Scotland, gabapentinoids were implicated in less than 1% of deaths in 2008 compared with 37% in 2024^​5​. This finding is despite changes to legislation passed in 2019 to restrict the supply of gabapentinoids by reclassifying them to a class C and schedule 3 controlled drug^​25​. The Advisory Council on the Misuse of Drugs (ACMD) is currently reviewing the evidence on the misuse and harms of gabapentinoids in the UK^​26​. 

Responses to changes in drug trends have been implemented across the UK, while strategies have been developed to monitor and respond to emerging trends and risks. In England, the Office of Health Improvement and Disparities published guidance on planning for and mitigating the effects of the arrival of potent synthetic opioids in 2024^​27​. In Scotland, Public Health Scotland (PHS) co-ordinates local intelligence and trends across the country and publishes a quarterly Rapid Action Drug Alerts and Response (RADAR) report to provide early warning of emerging drug trends and identify actions to reduce and prevent harms and deaths. PHS alerts are also published where significant risks are evident, such as those produced for nitazenes, xylazines and bromazolam^{​3,28,29​}. 

Treatment standards

Evidence-based standards for drug treatment have been introduced across the UK to improve the quality of care and consistency in delivery^{​30–32​}. The standards are designed to address issues, such as access to treatment, commencing treatment quicker, retention in treatment and involving the patient in the decisions about treatment.

Treatment choice is an important aspect within UK clinical guidance^​33​. Individuals accessing treatment should be included in the discussion and participate in making an informed decision on the treatment they would like to receive.

As an example, the medication-assisted treatment (MAT) standards in Scotland, published in May 2021, consist of ten individual standards relating to the care of individuals (see Table^​30​). Although originally introduced for opioid dependence, the principles and standards can be expanded to other substances. 

Examples of harm reduction activity

Naloxone provision and importance

Naloxone is an opioid receptor antagonist with a higher affinity for mu opioid receptors than most other opioids. It is also used for reversing opioid overdose because it quickly displaces and blocks the effects of other opioids^​34​. Although naloxone has a rapid onset of action, it has a short duration of action of around 30-90 minutes; therefore, if opioids are still circulating in the person’s system after this time period, they are at risk of relapsing back into overdose^​35​. 
 
Naloxone is a prescription-only medicine (POM) and is available in several formulations for administration via injection and intra-nasal routes. Although naloxone is a POM, the Human Medicines Regulations state that “anyone is permitted to administer naloxone to another individual in order to save their life in an emergency”. An exemption is also in place for any drug treatment services to enable supply of take-home naloxone without a prescription to people at risk of witnessing an overdose^​36​. UK legislation changes in December 2024 enabled a wider range of people to supply naloxone without a prescription^​37​.
 
In October 2023, the Scottish government, along with Community Pharmacy Scotland (CPS), agreed to add a naloxone emergency supply service to the community pharmacy public health service. This enables community pharmacies to hold a supply of naloxone for use in an emergency to any individual and ensures that pharmacy teams are suitably trained and equipped to be able to recognise an overdose and administer naloxone^​38​. The Scottish government has described this as the first phase, with a second phase being the role out of take-home naloxone, details for which are still to be agreed^​39​. National and local programmes exist across the UK to increase availability and access within communities^​40​. See ‘How to implement a naloxone supply approach in hospitals’ for more information.
 
National Records of Scotland data show that opiates/opioids were implicated in 80% of DRD in Scotland in 2024, which highlights the importance of naloxone being readily available in communities and individuals at risk of witnessing an overdose having a supply and training to recognise an overdose and administer this life-saving medicine^​5​.

Injecting equipment/foil provision and advice

Injecting drug use carries an inherent significant risk of harm, as it breaches the body’s defences and introduces foreign materials directly into the tissues and blood stream. The supply of sterile and appropriate drug administration equipment (IEP) — formerly ‘needle exchange’— is a well-evidenced harm reduction intervention^​41,42​, most commonly provided through community pharmacies.

Principally, introduced to reduce the transmission of BBVs via needle sharing, such as HIV and hepatitis C^​11​. This intervention also serves to reduce other injecting-related harms, such as wounds and bacterial tissue infections^​43​. Sharp, sterile, single-use needles/syringes, often with a design to minimise residual blood volume, are provided. Service users are additionally provided with appropriate paraphernalia, such as swabs, filters, acidifiers and spoons, to reduce risks associated with drug administration^​44​. Foil sheets, along with advice on use, may also be provided to encourage a change in drug administration route from injecting to smoking^​45​. 

Individuals smoking stimulant drugs may also have additional unmet care needs^​20​. Currently, pipes for using with crack cocaine are not allowed to be supplied; however, work is underway to generate robust evidence to inform legislative review and improve crack cocaine harm reduction services^​20​.

The use of image and performance enhancing drugs, such as steroids and weight-loss drugs, are a rapidly growing issue and may carry many of the same injecting-related risks, such as infection and wounds, but require different support^​46​. 

IEP services provide access to equipment, along with prevention education around risk factors to help reduce risky drug use. This includes demonstrations of equipment, advice on safer drug-use practices and referral to specialist care services for support, testing and treatment for infection. In addition, IEP services provide an avenue for the safe disposal of used equipment, reducing the risk of ‘contaminated’ sharps within communities. Anonymous demographic and drug use information is gathered within IEP services alongside the supply of equipment. This helps to support service improvement and identify changes in drug use.    

Lifetime treatment costs for HIV can range between £280,000–360,000^​47​ and a course of hepatitis C medication can cost around £13,000^​48​; therefore, sterile, single-use, ‘one-hit-kits’ which cost 22p, are well-justified from a health economics perspective. 

Impact of polysubstance use

Polysubstance use is a major risk factor for both non-fatal and fatal overdoses for people who use substances, some of which may be prescribed to the individual, including opioids, alcohol, gabapentinoids and benzodiazepines (i.e. CNS depressants). The most potent combinations likely to cause DRD are mixtures of substances, which may cause respiratory depression^​49​.

As many substances are illicit and are not subject to quality assurance, it is not possible to be confident of the type or quantity of substance being taken. This situation has recently been exacerbated through the contamination and/or substitution, either intentional or unintentional. For example, the presence of high potency opioids, such as nitazenes, being found in illicit products sold as benzodiazepines, opioids (e.g. heroin or oxycodone) and cocaine^​3​.