If opioids are risky, why are they still prescribed?

They are genuinely useful for short-term (acute) pain and for cancer and end-of-life pain, and occasionally help a minority of people with chronic non-cancer pain as part of a wider plan. The concern is long-term use for ordinary chronic pain, where benefits are often small and risks grow over time, so doctors use them cautiously, at low doses, with regular review.

Can I stop my opioid suddenly if I do not want it anymore?

No — stopping abruptly after regular use can cause unpleasant withdrawal and a rebound in pain. Ask your doctor for a gradual tapering plan, done slowly and with support. Many people feel no worse, or even better, on lower doses.

Is it safe to have a drink or take sleeping pills with my opioids?

No — alcohol, sleeping pills and sedatives combined with opioids can dangerously slow your breathing and cause overdose. Always tell your doctor and pharmacist about everything you take, including over-the-counter and traditional medicines.

Can I bring my opioid painkillers into or out of Singapore?

Strong opioids are controlled drugs in Singapore and usually require prior HSA approval to bring in, even for personal use, with limits on quantity. Never carry or send them for someone else, and check HSA’s rules before travelling — penalties for breaching controlled-drug rules are severe.

Opioids & Chronic Pain in Singapore: Risks & Safe Use

Q: What is the difference between tolerance, dependence and addiction?

Tolerance means you need more for the same effect; dependence means your body gets withdrawal symptoms if you stop suddenly — both are expected physical effects of regular use. Addiction is different: loss of control over use, craving, and continuing despite harm. You can be dependent without being addicted, but long-term use raises the risk of all three.

Written & reviewed by the BestDoctors.sg editorial team · Last updated 24 Aug 2026 · General information, not medical advice

Opioids are strong pain-relieving medicines — morphine, oxycodone, fentanyl, tramadol and others — that act on opioid receptors in the brain and body. They are effective for short-term (acute) pain and for cancer and end-of-life pain, but for chronic non-cancer pain the evidence for long-term benefit is weak and the risks grow with dose and duration, so they are generally not first-line. In Singapore they are prescription-only, and the stronger ones are controlled drugs regulated by HSA.

Living with pain that’s hard to control?

Message our care team on WhatsApp. Tell us what’s going on and we’ll help you find the right pain specialist — free, with no obligation.

Chat with our care team on WhatsApp

Not sure who to see? Find the right specialist →

In a medical emergency, or for severe or sudden symptoms such as breathing difficulty, chest pain, fainting or stroke signs, call 995 immediately.

Opioid overdose is life-threatening — excessive drowsiness or being unable to wake, slow or shallow breathing, pinpoint pupils, or bluish lips — call 995, and place the person on their side while you wait.

Key principles

Decisions about opioids are best made together with a doctor, with clear, realistic goals focused on improving function and quality of life rather than chasing a pain score of zero, which is usually not achievable in chronic pain. Opioids are not first-line: non-drug and non-opioid options are tried first and kept going alongside any medicine. If opioids are used, the approach is “start low, go slow” as a time-limited trial with agreed review points; higher doses rarely add benefit but do add harm. If the opioid is not clearly improving both pain and function, or if harms outweigh benefit, the plan is to taper and stop — slowly, to avoid withdrawal. Stopping an unhelpful opioid is a normal, expected outcome, not a failure.

Tolerance, dependence and addiction

These three are often confused. Tolerance means needing more for the same effect; dependence means getting withdrawal symptoms if a dose is missed or stopped abruptly — both are expected physical effects of regular use. Addiction is different: craving, loss of control over use, and continuing despite harm. You can be physically dependent without being addicted, but long-term use raises the risk of all three, and risk is higher with higher doses, longer duration, and a personal or family history of substance-use or mental-health problems.

When harms appear

Signs the opioid is causing more harm than good include needing ever-higher doses for the same effect, pain no better despite increases, worsening mood, poor sleep and reduced activity, or paradoxically increasing sensitivity to pain. Common side effects are constipation, nausea, drowsiness, itch and dry mouth; longer-term effects can include hormonal changes, and in older adults falls and fractures. Withdrawal — sweating, chills, stomach cramps, body aches, anxiety and rebound pain — can occur if a dose is missed or stopped suddenly. Signs of a developing problem to raise with a doctor include needing the medicine to feel “normal,” anxiety about running out, or using it for stress or sleep.

Safety

Overdose risk rises after a dose increase, after a break in use (tolerance drops fast, so restarting the old dose can be fatal), and when opioids are mixed with alcohol, sleeping pills, benzodiazepines or other sedating medicines — avoid these combinations unless specifically supervised. Do not exceed the prescribed dose, double up missed doses, crush modified-release tablets, take anyone else’s opioids, or drive when drowsy. Store them securely away from children (a single adult dose can be fatal to a child) and dispose of unused supply through a pharmacy. Because strong opioids are controlled drugs in Singapore, bringing them into or out of the country usually needs prior HSA approval, with quantity limits, and penalties for breaching controlled-drug rules are severe.

Using opioids as safely as possible

If you and your doctor do decide on a trial of opioids, a few habits keep the risks as low as possible. Take them exactly as prescribed, at the agreed dose and timing, and never top up a missed dose or use them to manage stress or sleep — if the pain or the reasons for taking them are changing, that is a conversation to have with your doctor rather than a cue to take more. Agree clear review points from the start, and be honest at each review about whether the medicine is actually improving your function, not just momentarily dulling pain. Keep a current list of everything you take, including over-the-counter and traditional medicines, so interactions can be checked, and avoid alcohol and sedatives. Store the medicine securely and out of reach of children and visitors, and return any unused supply to a pharmacy rather than keeping or sharing it. If you have been on opioids for a while and want to reduce them, ask for a supported, gradual taper — many people find their pain is no worse, and their thinking clearer, on a lower dose or none at all. Treat any sign of overdose in yourself or someone else as an emergency.

Better alternatives and when to see a doctor

For most chronic non-cancer pain the mainstay is non-opioid and non-drug: physiotherapy and graded exercise, staying active, weight and sleep management, psychological therapies such as CBT and pain self-management programmes, and — for nerve pain — certain antidepressants or anti-seizure medicines. Chronic pain is ideally managed by the GP and, where needed, a pain specialist or multidisciplinary pain clinic. See a doctor before starting opioids to weigh benefits and risks, if pain is not improving or you are needing more of the medicine, if side effects are troubling, or if you notice signs of dependence and want a supported taper — and never stop suddenly on your own. Any overdose warning sign is a 995 emergency.

Sources

CDC — Clinical Practice Guideline for Prescribing Opioids for Pain (2022): cdc.gov
NHS England — Reducing long-term opioid use: england.nhs.uk
Faculty of Pain Medicine (UK) — Opioids Aware (information for patients): fpm.ac.uk
Health Sciences Authority (HSA) Singapore — therapeutic products regulation: hsa.gov.sg

General information only. This guide is general information about a pain condition or treatment and is not a diagnosis or personalised medical advice. See a doctor — a GP or a pain specialist — for assessment and a treatment plan. Seek urgent care for pain after a major injury, a fever with severe pain, new leg weakness or numbness, or loss of bladder or bowel control (possible nerve compression). Call 995 for signs of an opioid overdose — excessive drowsiness, very slow or shallow breathing, or a person who cannot be roused.

Opioids and Chronic Pain in Singapore: A Safety Guide