ADVOCACY
The increasing availability of substances like nitazenes and xylazine in the drug supply is raising vital questions that extend way beyond any individual substance, says Riley Johnson
HIDDEN DEPENDENCE
T he UK drug market is changing, and with it comes a challenge that many treatment services are only just beginning to experience. The emergence of substances such as xylazine, nitazenes and medetomidine as contaminants in the market has raised urgent questions for those providing treatment and OST. While often discussed in the context of overdose risk and drug-related deaths, the question of what happens when people become dependent on the contaminants has received far less attention.
Through the Release helpline, we supported an individual who suspected that they were dependent on nitazenes. They had been started on methadone and titrated up, but still experienced significant withdrawal symptoms. TH’ s drug service explained that they were not comfortable increasing the methadone past 90mg, and that TH’ s dose should be sufficient based on the amount of heroin they reported using. We supported TH in posting a sample of their heroin for drug testing, and it came up positive for nitazenes. After presenting these results to TH’ s drug service it was agreed that they would increase the dose but were eager to reduce it again as soon as TH was stable.
Current guidance offers a clear framework for managing
opioid dependence. Methadone and buprenorphine remain highly effective treatments, but neither medication is designed to treat dependence on non-opioid adulterants. Nitazenes, which are opioids, can also add an extra layer of complexity. They can in principle be managed through OST, but their potency means that the reported amount of heroin use is often a poor indicator of what the person’ s tolerance really is.
The reported amount of heroin use is often a poor indicator of what the person’ s tolerance really is.
As a result, services increasingly find themselves navigating a clinical territory for which there is little formal guidance. Xylazine is a veterinary sedative with effects that differ significantly from opioids and medetomidine, another veterinary sedative increasingly detected in illicit drug supplies, acts in a similar way. As neither substance is an opioid, neither is addressed by methadone or buprenorphine. This creates a potentially confusing situation for clinicians and drug workers. Someone may start OST and still report severe anxiety, insomnia, agitation or distress. Historically, practitioners might interpret these symptoms as evidence that the opioid dose is too low or that treatment is not yet adequately stabilised, but what if the symptoms relate to withdrawal that cannot be managed through opioid treatment?
Where drug-checking is available, it can help to identify emerging adulterants which clients may be using, or dependent on. For frontline services, this information can help explain unexpected presentations, unusual withdrawal symptoms and difficulties stabilising on OST. Drug testing strips are becoming more available, often offered in drug services and NSPs, though medetomidine testing strips can be difficult to come by, depending on the area.
At present, evidence regarding dependence on xylazine and medetomidine is still emerging. Much of the available literature comes from North America, and there is no established UK protocol for managing people who are dependent on these substances alongside opioids.
A useful starting point may be to recognise that, while provision of OST remains essential, it may not always be enough. Services may need to ask new questions – do we have up-to-date data on the
local drug trends? Are clients reporting longer periods of sedation or experiencing their drugs differently than they are used to? Are withdrawal symptoms presenting differently? Are multiple clients describing similar experiences?
Perhaps most importantly, services should take clients ' reports seriously. Someone explaining that the methadone is helping but something still feels wrong, or that they are finding that their heroin is cooking up differently, or affecting them differently, should prompt further exploration rather than assumptions of non-compliance or‘ treatment failure’.
While there is currently no consensus on the optimal management of dependence on xylazine or medetomidine, several principles seem likely to become increasingly important. The appearance of xylazine, nitazenes and medetomidine in the drug supply raises a question that extends beyond any individual substance. Increasingly, people may present to treatment dependent not just on the drug they sought to buy, but on a complex combination of compounds added along the supply chain.
People cannot be expected to fit neatly within existing guidance when the drug market itself no longer does. Our responsibility is not merely to treat the dependence we anticipate or that is described in guidance, but the dependence that is actually showing up in treatment services today.
Riley Johnson is drugs support advisor and NSP specialist at Release
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