Painkillers and anti-inflammatory medicines

What are painkillers and anti-inflammatory medicines, and how do they work?

Analgesics (painkillers) are medicines that ease pain. NSAIDs, such as aspirin, ibuprofen and diclofenac, also reduce inflammation (redness and swelling) and lower fever¹. They work by stopping injured cells from making prostaglandins, the chemicals that cause inflammation and swelling¹. That eases pain, but it isn't a cure².

Paracetamol is often the first medicine suggested for short-term pain³. The right choice depends on the pain. Paracetamol and anti-inflammatories are most effective for pain caused by inflammation, such as an injury or arthritis, while pain from sensitive or damaged nerves usually needs a different type of medicine⁴.

What are they used for, and how well do they work?

For sprains, strains and whiplash in adults, topical NSAIDs (gels or creams rubbed on the skin) gave the best balance of benefit and harm, followed by NSAID tablets or paracetamol⁵. For knee osteoarthritis (wear-related joint pain), topical NSAIDs are strongly recommended⁶. For hip or widespread osteoarthritis, NSAID tablets are favoured, because a gel isn't expected to reach a deep joint⁶.

Expect modest relief. Some NSAID tablets give clearly meaningful pain relief in knee and hip osteoarthritis, but paracetamol gives only a small benefit⁷, and it didn't speed recovery from sudden low back pain⁸. After surgery, many people don't get good relief⁹, and most medicines for long-term pain help only a minority of people¹⁰. Tablets can take up to an hour to start working, and a gel or cream up to 2 days for its full effect².

Are they right for me?

Most adults can take NSAIDs¹¹, but you shouldn't if you're allergic to them, pregnant or planning a pregnancy, or have a kidney or liver condition or a gut ulcer or bleeding¹. They're not usually recommended while breastfeeding¹¹. Avoid them, or take particular care, if you have asthma, Crohn's disease, ulcerative colitis, heart problems or a bleeding disorder⁴.

Being over 65, dehydrated or already taking another NSAID raises the chance of side effects, and older people shouldn't use NSAIDs regularly¹. Older adults and people with high blood pressure or heart disease need a careful weighing of benefit and risk⁵. For knee osteoarthritis, a gel or cream is favoured if you're frail or have stomach or heart conditions, because less reaches the rest of your body⁷.

The evidence here is in adults. Get advice from a doctor or pharmacist before giving any of these medicines to a child.

What should I expect when I use them?

Over-the-counter medicines are usually suitable for mild-to-moderate pain³. Read the label, follow the amount your pharmacist or doctor advises, and don't go over it⁴. Use the lowest amount that controls your pain, for as short a time as you can, ideally only when you need it rather than every day⁷. Taking NSAID tablets with food lowers the chance of stomach upset¹.

If your pain improves, ask your pharmacist or GP whether you can reduce or stop the medicine, which helps cut side effects². Don't take someone else's medicine.

What are the risks and side effects?

NSAIDs can cause stomach ulcers or bleeding, kidney problems and serious allergic reactions¹¹. They're also linked with high blood pressure and heart disease¹². The chance of side effects goes up if you're over 65, take more than the recommended amount, take them for a long time, or take more than one NSAID¹. Gels and creams cause more skin reactions than a dummy treatment, but fewer stomach problems¹³.

Regular large doses of paracetamol can damage the liver¹⁴.

Opioids (strong prescription painkillers) can be addictive and cause life-threatening breathing problems, even when taken as prescribed³. If you stop suddenly or cut back too fast you can get withdrawal, so any reduction should be gradual and supervised by a healthcare professional¹⁰. Alcohol and other sedating medicines add to the breathing and drowsiness risk¹⁵, and opioids may not be safe with obstructive sleep apnoea¹⁰.

How do they compare with other options?

Guidelines put non-opioid options ahead of opioids for common pain. Opioids aren't recommended first for low back pain, sprains and strains, because NSAIDs work as well or better and opioids carry risks of long-term use⁵. For osteoarthritis, the benefit of opioids doesn't outweigh the harm⁷.

Medicines also aren't the only choice. Exercise is strongly recommended for osteoarthritis, alongside gels for the knee⁶. For sudden low back pain, non-drug options such as a heat pack or massage come first, with NSAIDs or muscle relaxants if you want a medicine¹⁶. If paracetamol alone isn't helping, ask your pharmacist or GP about other options.