Paracetamol or ibuprofen: which one, and when

Almost every household has both, often in the same drawer, and most people reach for whichever comes to hand first. They are not the same medicine, though. They work in different ways, they suit different problems, and one of them is considerably riskier than the other for certain people. Ten minutes of understanding here can save you a lot of discomfort.

What each one actually does

Paracetamol, which you may also see sold as acetaminophen, brings down fever and dulls pain. It works mainly in the brain and spinal cord, changing how pain signals are received rather than treating what is causing them. What it does not do is reduce inflammation. For a headache, a fever, or general aches it is usually the sensible first choice, and it is gentle on the stomach.

Ibuprofen belongs to a family called non-steroidal anti-inflammatory drugs. Alongside relieving pain and fever it reduces swelling and inflammation at the site of the problem. That makes it the better choice where something is visibly or obviously inflamed: a sprained ankle, period pain, toothache, back pain, an injury that has swollen.

A rough guide to choosing

• Fever, headache, general aches — paracetamol first.
• Sprains, swelling, period pain, toothache, back pain — ibuprofen tends to work better.
• Sensitive stomach, ulcers, reflux — paracetamol, and avoid ibuprofen unless a doctor has said otherwise.
• Children — both exist in syrups, but the dose depends on weight. Ask us rather than guessing.

The rules that matter most

With paracetamol, the single most important thing is not to exceed the maximum daily amount on the label, and to remember that it hides inside a great many combination products. Cold and flu sachets, night-time remedies and some pain tablets all contain it. People overdose by accident far more often than deliberately, simply by taking a cold remedy and paracetamol tablets together without realising they are taking a double dose. Check every box.

With ibuprofen, the key is to take it with or just after food, to use the lowest dose that works, and to use it for as short a time as possible. It can irritate the stomach lining, and in some people it causes ulcers or bleeding. It also affects the kidneys, which matters if you are dehydrated, and it can raise blood pressure.

Who should be careful with ibuprofen

• Anyone with a history of stomach ulcers or bleeding.
• Anyone with asthma that has ever been triggered by a painkiller.
• Anyone with kidney problems, heart failure or uncontrolled blood pressure.
• Anyone in the later part of pregnancy — paracetamol is generally preferred throughout.
• Anyone taking blood thinners, steroids, or certain blood-pressure medicines.
• Anyone who is dehydrated, including during a bout of vomiting or diarrhoea.

That last one catches people out during fevers and stomach upsets, exactly when they are most likely to reach for a painkiller. If you are not keeping fluids down, paracetamol is the safer option and rehydration matters more than either.

Can you take both together?

They work differently, so they can be combined for short periods under advice, and sometimes they are alternated for a stubborn fever. That is not something to improvise, though, particularly with children, where the timing and the doses need to be written down and followed exactly. Ask a pharmacist to set it out for you rather than working it out at two in the morning.

When pain relief is not the answer

Painkillers treat the symptom. If you are taking them most days, something underneath needs attention, whether that is a tooth, a joint, a recurring headache pattern or something else. Regular use of either medicine over weeks and months carries its own risks, and in the case of headaches, frequent painkiller use can itself become the cause of the headaches.

Come and talk to us if you are buying pain relief more often than occasionally. Sometimes the answer is a different medicine, sometimes it is a referral, and sometimes it is something simple nobody has mentioned yet.

What about aspirin and diclofenac?

Diclofenac belongs to the same family as ibuprofen and carries the same cautions, generally a little more strongly. It is effective for joint and muscle pain, and it is widely available as a gel you rub in, which puts much less of the medicine into your bloodstream than a tablet does. For a localised ache in a knee or a shoulder, the gel is often the more sensible choice.

Aspirin is the oldest of the group and is still a good painkiller, but it irritates the stomach more than most and it should never be given to children because of a rare but serious complication. Many people also take a very low dose of aspirin daily to protect the heart. That is a completely different use at a completely different dose, and it should not be stopped or doubled without advice.

Things that are not in a packet

For a tension headache, water and a short break from a screen often do more than a tablet. For period pain, heat on the lower abdomen genuinely helps and works well alongside ibuprofen. For a sprain, the first day or two of rest, a cold pack and elevation will reduce swelling more than any medicine. For back pain, gentle movement beats lying still, which surprises people but is well established.

None of this means refusing pain relief. It means the tablet is one part of the answer rather than the whole of it, and the other parts cost nothing.

Signs that a painkiller is the wrong tool

• A headache that is sudden and severe, or different from any you have had before.
• A fever in a baby under three months, or a fever with a rash that does not fade under pressure.
• Abdominal pain that is getting worse rather than better, especially on the lower right.
• Chest pain, or pain spreading into the jaw or the arm.
• Pain after an injury where you cannot put weight on the limb or it looks misshapen.

In each of those, the pain is information rather than the problem, and covering it up delays the thing that actually needs doing. Seek help rather than reaching for the drawer.

A quick safety check before you take either

• Read every box you are taking and add up the total paracetamol.
• Take ibuprofen with or just after food, never on an empty stomach.
• Do not take ibuprofen while dehydrated from vomiting or diarrhoea.
• Use the lowest dose that works, for the shortest time that works.
• For children, work from weight rather than age, and ask us to write it down.

Questions we are asked about this

How long can I keep taking these before I should see somebody?

For a new pain, a few days of either is reasonable. If you are still needing pain relief after about three days without improvement, or you are taking something most days for more than a week or two, that is the point to be assessed rather than to buy another packet.

Is it safe to give both to a child?

They can be alternated for a stubborn fever, but the doses and the timing must be worked out for your child's weight and written down. This is not something to improvise at night. Bring your child's weight to us and we will set it out on paper for you.

Does a higher dose work better?

No. Above the recommended dose you gain very little extra pain relief and take on considerably more risk, particularly to the liver with paracetamol and to the stomach and kidneys with ibuprofen. If the recommended dose is not controlling the pain, the answer is a different approach rather than more tablets.

What about the painkillers sold mixed with caffeine or codeine?

They have their place for short-term use, but codeine-containing products can cause dependence and rebound headaches when used regularly, and they are not suitable for children or for breastfeeding mothers. Ask before using one for more than a few days.

This article is general information from the Dantrio Pharmacy team. It cannot take the place of advice from a pharmacist or doctor who knows your medical history. If you feel seriously unwell, seek medical help straight away.