What is opioid tolerance loss and why is it dangerous during self-tapering?

When someone takes an opioid regularly, the body adapts: receptor populations change and clearance mechanisms adjust, so the dose that once felt sedating becomes the dose that just manages pain. If a person significantly reduces their intake for several weeks, that tolerance begins to drop. If they then return to the dose they were previously prescribed, the body responds as though it is a much higher dose than it is accustomed to, raising the risk of respiratory depression and toxicity. The problem is invisible — the person may feel they have been managing fine at the lower dose, without knowing their risk threshold has shifted.

What does supervised opioid tapering look like in general practice?

Australian RACGP guidelines recommend reducing opioid doses by no more than 10 percent per four weeks, with regular check-ins to monitor pain levels, withdrawal symptoms, mood, and function. The pace can be adjusted based on how the individual responds. Importantly, tapering without addressing the underlying pain means the taper is harder to sustain — good opioid deprescribing involves building non-opioid pain management strategies alongside the dose reduction, not just cutting the prescription. The conversation with your GP about wanting to reduce is the necessary first step.

Self-tapering opioids without support can be fatal — a coroner's finding

What just happened

A Victorian coroner’s inquest, published this week, has documented a pattern that many people living with chronic pain will recognise — even if they have never spoken about it aloud.

Linda Bridle was 72. She had been prescribed tapentadol — an opioid painkiller — along with fluoxetine. She received a two-week supply from her GP, then did not request a repeat prescription for two months. Deputy coroner Paresa Spanos concluded that Ms Bridle had been quietly taking less than her prescribed dose — trying to wean herself off her opioid, without telling her doctor. When she returned to the full dose, she died from medication toxicity.

The coroner’s observation was careful and important: “not all drug-dependent behaviour looks alike.” What this case illustrates is not a person seeking more medication but the opposite — a person trying to need less of it, alone, without the medical support that could have made that safe.

Both-and

The desire to reduce is valid — and common

If you have been prescribed an opioid for chronic pain and you want to come off it, you are not alone and you are not wrong. Opioids carry significant long-term risks: tolerance and physical dependence, cognitive effects that compound over time, hormonal disruption (a condition called opioid-induced endocrinopathy), and opioid-induced hyperalgesia — a paradox where the painkiller eventually amplifies pain sensitivity rather than reducing it.

The desire to taper is medically sound. Australian prescribing guidelines from the RACGP acknowledge that long-term opioid therapy for non-cancer chronic pain should be regularly reviewed, and that reducing to the lowest effective dose — or discontinuing — is often the appropriate goal.

The problem is that many patients do not raise the desire to taper with their GP. Sometimes because they fear judgment. Sometimes because they have felt, correctly or not, that the system that started them on the medication has no interest in the conversation about coming off it. Sometimes because they have tried to raise it and were given a repeat prescription rather than a tapering plan.

And so they do it alone.

The physiology of going it alone

Here is the mechanism that makes unilateral tapering dangerous, and it is worth understanding precisely.

When you take an opioid regularly, your body adapts. Receptor populations change. Clearance mechanisms adjust. The dose that once made you drowsy becomes the dose that just manages your pain — your tolerance has risen to meet it.

When you stop or significantly reduce your intake over weeks or months, that tolerance begins to drop. Your nervous system recalibrates. If you then take the dose you were previously prescribed — the dose that was once your normal — your body responds to it as though it is much higher than it is accustomed to. The risk of respiratory depression and toxicity is real.

The combination of tapentadol and fluoxetine adds a layer of complexity. Tapentadol has a dual mechanism: it is both an opioid and a noradrenaline reuptake inhibitor. Fluoxetine affects serotonin pathways. Both drugs interact with neurotransmitter systems that matter to pain, mood, and respiratory drive. The Australian Commission on Safety and Quality in Health Care flags opioid combination risks as a priority area in medication safety precisely because these interactions are underrecognised and underreported.

The system’s role

The coroner’s finding is not primarily a story about a patient’s decision. It is a story about a system that does not always create space for the conversation a patient needs to have.

When someone is on a long-term opioid prescription and wants to reduce, the path to do that safely is not obvious. Opioid tapering protocols exist — RACGP guidance recommends reducing by no more than 10 percent per four weeks, with regular monitoring, and building non-opioid pain management strategies alongside the dose reduction. That requires time, relationship, and a GP who is ready to hold that conversation non-judgmentally.

The coroner was careful to note that Ms Bridle’s pattern — receiving a prescription but not filling repeats — did not look like typical medication-seeking behaviour. It looked like someone trying to do the right thing, quietly, without burdening anyone. That is the part that sits uncomfortably: the framing of responsibility onto the patient, when the system did not offer a better path.

My two cents

If you are on a painkiller and you have been quietly taking less than prescribed — please tell your GP.

Not because you have done something wrong. But because the gap between “I am managing at half my usual dose” and “I could be seriously harmed if I take the full dose again” may be smaller than you know. Tolerance loss is not visible. It happens silently, over weeks, without any warning signal.

Supervised tapering is not the same as cutting back alone. A planned reduction — with a clear schedule, monitoring, and support for managing the pain that re-emerges as the medication reduces — is a medically very different process from the informal, hope-it-works version most people attempt when they cannot find the words to start the conversation.

You have every right to want to reduce your opioid load. If you do not feel you can have that conversation with your current GP, finding one who will support a proper tapering plan is a legitimate path. The conversation the coroner describes Ms Bridle as never having had is available — it just needs to be asked for.

Verdict: yes — worth knowing about, particularly if you or someone you know is on a long-term opioid prescription and thinking about reducing.

Sources cited

‘Not all drug-dependent behaviour looks alike’: Coroner on 72-year-old who tried to wean herself off painkillers. AusDoc, 6 August 2026. https://www.ausdoc.com.au/news/not-all-drug-dependent-behaviour-looks-alike-coroner-on-72-year-old-who-tried-to-wean-herself-off-painkillers/
Prescribing drugs of dependence in general practice — clinical guidelines. RACGP. https://www.racgp.org.au/clinical-resources/clinical-guidelines
Opioid medicines — medication safety. Australian Commission on Safety and Quality in Health Care. https://www.safetyandquality.gov.au/our-work/medication-safety/opioid-medicines