Understanding Painkillers

Painkillers do not all treat the same problem. A medicine useful after surgery may be unsuitable for chronic primary pain or nerve pain. Safe choices depend on the cause and duration of pain, other treatments and the person's health.

Painkillers are not one simple hierarchy An analgesic is a medicine used to reduce pain. Painkillers differ in how they work, which pain conditions they help and which harms they can cause. A stronger medicine is not automatically a better match. Pain after surgery, inflammatory joint pain, nerve pain, cancer pain and chronic primary pain may require different approaches. Medicines are only one part of pain care. Depending on the condition, treatment may also include movement, rehabilitation, psychological approaches, procedures or treatment of the underlying cause. Paracetamol has a specific but limited role Paracetamol can reduce pain and fever. Its exact pain relieving mechanism is not fully understood, and it has little anti inflammatory effect at usual doses. It can help some acute pain and is used in several condition specific pathways. It is not effective enough for every pain condition and is not automatically the safest choice for everyone. Paracetamol appears in many combination, cold and flu products. Taking more than one paracetamol containing product can unintentionally exceed the recommended amount. Too much paracetamol can cause serious liver damage, and early symptoms may be absent. Contact NHS 111 immediately after taking more than the packet or leaflet recommends, even if you feel well. NSAIDs reduce pain and inflammation Non steroidal anti inflammatory drugs, or NSAIDs, include ibuprofen and naproxen. They reduce production of prostaglandins involved in pain, inflammation and fever. Prostaglandins also help protect the stomach and support kidney blood flow. Oral NSAIDs can cause ulcers, bleeding, kidney injury, fluid retention and cardiovascular harm in susceptible people. Risk depends on the medicine, dose, duration and person. Pregnancy, asthma, previous ulcers, kidney or heart disease, anticoagulants and other medicines can change suitability. Topical NSAIDs can provide local treatment with lower average systemic exposure than tablets. They can still cause adverse effects and are not suitable for everyone. Use the lowest effective NSAID dose for the shortest necessary time. Do not take two NSAIDs together unless a healthcare professional has specifically advised it. Opioids have important uses and important risks Opioids include codeine, morphine, oxycodone, fentanyl and tramadol. They act mainly at opioid receptors and can reduce moderate or severe pain. They can be appropriate for selected acute pain, cancer pain and palliative care. Their role depends on the clinical context rather than a universal final step. Opioids can cause nausea, constipation, drowsiness, falls and dangerous breathing suppression. Longer use can produce tolerance and physical dependence, and some people develop addiction. Opioids may also become less helpful during prolonged treatment. A person taking long term opioids can develop increased sensitivity to pain, called opioid induced hyperalgesia. When opioids are appropriate, the treatment aim and stopping plan should be agreed. They should not be started for chronic primary pain under current NICE guidance. Nerve pain may need different medicines Neuropathic pain results from a lesion or disease affecting the somatosensory nervous system. Ordinary painkillers may provide limited benefit for some neuropathic conditions. Medicines such as amitriptyline, duloxetine, gabapentin or pregabalin may be considered for selected neuropathic pain. They have different mechanisms and their own adverse effects and withdrawal risks. These medicines are not suitable for every condition described as nerve pain. For example, treatment recommendations for sciatica and trigeminal neuralgia differ. Chronic primary pain needs a separate approach Chronic primary pain persists or recurs for more than three months. It is not adequately explained by another condition, or its impact is disproportionate to observable injury or disease. NICE advises against starting paracetamol, NSAIDs or opioids for chronic primary pain. Selected antidepressants may be considered after discussion, even when the person does not have depression. This does not mean the pain is psychological or unreal. It means the expected benefits and harms differ from those in acute injury, inflammatory pain or cancer pain. Combining medicines can help, but is not automatically safer Using medicines with different mechanisms is sometimes called multimodal analgesia. It can improve pain control and reduce opioid requirements in settings such as perioperative care. The benefit is condition specific. Combining medicines adds their adverse effects and interactions, and it may duplicate an ingredient without the person realising. Co codamol contains paracetamol and codeine. Taking separate paracetamol alongside it can produce an accidental paracetamol overdose. Some products combine an NSAID with an opioid. Taking another NSAID at the same time can increase gastrointestinal and kidney risk. Check every active ingredient rather than relying on the brand name. Combining painkillers should follow the packet, prescription or advice from a pharmacist or prescriber. The pain ladder has a limited context The World Health Organization developed a stepwise analgesic ladder for cancer pain. Stepwise approaches are also used in some palliative and acute pain settings. The ladder is not a universal rule for every pain condition. Osteoarthritis, neuropathic pain, migraine and chronic primary pain follow different evidence based pathways. For knee osteoarthritis, core treatment includes therapeutic exercise and weight management when appropriate. NICE recommends a topical NSAID and does not routinely recommend paracetamol or weak opioids. Pain treatment should therefore match the diagnosis, duration, severity, functional impact and individual risks rather than automatically climbing towards an opioid. When urgent help is needed Contact NHS 111 immediately if you have taken more paracetamol than the packet or leaflet recommends, even if you feel well. Get urgent advice after taking too much ibuprofen, naproxen, codeine or another painkiller. Bring the packet and details of every product taken. Call 999 for severe breathing difficulty, a seizure, collapse, unresponsiveness or very slow or stopped breathing after a painkiller. Contact NHS 111 urgently for vomiting blood, black sticky stools or suspected serious NSAID effects. Call 999 when severe bleeding causes collapse, breathing difficulty or marked weakness. This lesson explains general principles. It cannot identify the correct pain treatment or safe dose for an individual person.

Painkillers are different tools, not fixed steps on one universal ladder. Safe treatment matches the medicine to the pain condition and person, while checking dose limits, duplicate ingredients and context specific risks.