Tramadol: how it works, slow-release forms and dependence risk

The NHS describes tramadol as a strong painkiller from the opioid group, used for moderate to severe pain. A doctor may prescribe it for severe pain if weaker painkillers do not help. It acts on pain receptors in the central nervous system and brain, blocking pain signals and stopping the brain receiving pain messages. It does not stop pain completely, but makes it much less noticeable.

It is available only on prescription, which reflects the need for a prescriber to review benefit, duration and risk of dependence.

The speed and duration of effect depend on the form, and mixing them up is a common source of problems. The doctor decides the dose by considering pain sensitivity, severity, previous response to painkillers and side effects, and the dose may be adjusted several times to find the lowest one that works.

• Standard tablets and capsules, drops, soluble and orodispersible tablets: work within 30 to 60 minutes and are used for short-lived or intermittent pain. They are usually taken 3 to 4 times a day.

• Slow-release tablets and capsules: release the medicine over 12 or 24 hours, take longer to start, last longer and are used for severe pain. They are usually taken once or twice a day. Swallow whole; never break, crush, chew or suck them, because the whole dose could reach the body at once and cause an overdose.

• If you are 65 or over, or have liver or kidney problems, the doctor may advise taking it less often.

More than 1 in 100 people get headaches, sleepiness or dizziness (sometimes described as feeling spaced out), nausea or vomiting, constipation, a dry mouth, sweating or low energy. The NHS suggests simple measures such as taking it after food, fibre, fluids, sugar-free gum or loose clothing, and says to speak to a doctor if they persist.

Less common serious effects include dizziness or weakness from low blood pressure, hallucinations, confusion, being very sleepy and trouble peeing; call your doctor or 111. Call 999 or go to A&E for a seizure or fit, breathing difficulties, short shallow breathing, or signs of anaphylaxis.

Most adults and children aged 12 and over can take tramadol. Tell the prescriber if you have had an allergic reaction to it, have a condition causing seizures, a head injury, an addiction to alcohol, strong painkillers or recreational drugs, breathing difficulties, kidney or liver problems, a reaction to other strong painkillers, or are pregnant, breastfeeding or trying for a baby.

In pregnancy the NHS says tramadol might be the best option for severe pain, ideally for only a few days; it is not known to cause problems with development, though more studies are needed, and babies exposed late in pregnancy may have withdrawal such as feeding or breathing problems. It passes into milk in very small amounts and might make a baby sleepy, so breastfed babies should be watched and bed-sharing avoided. There is no good evidence it reduces fertility in men.

Tell your doctor about medicines for depression or other mental health problems, other painkillers, sleeping medicines, anxiety medicines, antihistamines, blood thinners such as warfarin and anti-infectives. Carbamazepine, buprenorphine, ondansetron and rifampicin may weaken or shorten its effect.

Do not take it with MAOIs. It is safe with paracetamol or ibuprofen, but not with codeine-containing products such as co-codamol, Nurofen Plus or Solpadeine. Try to avoid alcohol in the first few days, and stop it if you feel sleepy. Cannabis, cocaine and heroin increase the chance of breathing difficulties, heart problems and seizures, and MDMA, cocaine, amphetamines or LSD can cause serotonin syndrome, whose severe signs include very high temperature, seizure, irregular heartbeat and loss of consciousness.

Long use can cause tolerance and hyperalgesia (extra sensitivity to pain), and addiction is possible. Signs include finding it hard to stop or feeling the need to take it more than necessary. Withdrawal may include agitation, anxiety, panic attacks, palpitations, poor sleep, shaking, sweating, body aches and restlessness. Do not stop abruptly after more than a few weeks; the dose is normally reduced gradually.

Do not drive, cycle or use tools if tramadol makes you sleepy, dizzy, clumsy, blurry-eyed or unable to concentrate; this can occur at the start or when another medicine is added. Never double a dose if you forget one, and never take more than prescribed. If two or more extra doses are taken, seek urgent advice.