What are painkillers (analgesics)?

Simple non-opioid analgesics

Compound analgesics

Opioid analgesics

Which medications can help with osteoarthritis?

Which medications can help with inflammatory arthritis?

What medications are used in nerve (neuropathic) pain?

What if I have problems with my heart?

What are painkillers?

Painkillers are drugs that help to reduce pain. When we talk about painkillers, we are usually referring to a group of drugs called analgesics. There are three different types of analgesics, as shown in Table 1.

Drugs may be available under several different names. Each drug has an approved (or generic) name but manufacturers often give their own brand or trade name to the drug as well. For example, Nurofen and Panadol are brand names for ibuprofen and paracetamol, which are their approved names. The approved name should always be on the pharmacist’s label even if a brand name appears on the packaging, but check with your doctor, nurse or pharmacist if you are in any doubt. We will use the approved names in the sections that follow.

You do not need to wait until your pain is severe to use analgesics. Take them as the packet advises or as your doctor suggests. Many people find that analgesics are not as effective as they could be because they do not take them early enough or often enough.

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Simple non-opioid analgesics

Simple non-opioid analgesics are the most common type of analgesic. The most common of these is paracetamol.

Paracetamol

Paracetamol is available over the counter and is widely used as a painkiller for mild to moderate pain, for example following a minor injury, and for headaches and muscular pains. Paracetamol will also reduce a fever. Side-effects are rare, though a few people may develop a rash.

There has been some concern that paracetamol may be linked to adverse effects on the cardiovascular system and kidneys, so it may be best used with caution over the long term. Your doctor may suggest stopping it from time to time to see if it is still necessary and helpful.

At doses higher than 4,000 mg (eight tablets) per day, paracetamol can seriously damage your liver. The number you can buy at any one time is limited because of this risk. Care must be taken if you have liver problems or drink a lot of alcohol. It must also be used in lower doses if you have kidney problems. Talk to your doctor about this if you are concerned.

Be aware that many other products, for example cold and flu medications, contain paracetamol.

Paracetamol is well tolerated during pregnancy or breastfeeding as long as it is not taken regularly or in doses of more than 2,000 mg per day.

Paracetamol does not have an anti-inflammatory effect, which means it is less helpful on its own for inflammatory arthritis, such as rheumatoid arthritis. For inflammatory types of arthritis paracetamol is commonly taken in combination with non-steroidal anti-inflammatory drugs (NSAIDs).

Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs are a type of simple non-opioid analgesic. They work by blocking enzymes called COX 1 and COX 2 (COX stands for cyclo-oxygenase). Both of these enzymes are important in causing inflammation but also have other important effects in the lungs, stomach and kidneys. Some NSAIDs block both enzymes while others were developed to specifically block COX 2. The latter are sometimes called coxibs. They were designed to reduce inflammation but with fewer side-effects, particularly on the digestive system.

If you may be at risk of ulceration or bleeding of the digestive system your doctor may recommend:

  • either a coxib – such as celecoxib or etoricoxib
  • or a standard NSAID (e.g. ibuprofen, naproxen) along with another drug called a proton-pump inhibitor (PPI) which reduces the risk of gastrointestinal irritation. Omeprazole and lansoprazole are commonly used PPIs.

NSAIDs and coxibs help to reduce inflammation, and also reduce pain and high body temperatures (if present). They can be used in combination with other simple or compound analgesics. Although there is little inflammation in osteoarthritis, a short course of NSAIDs can be helpful for some people – your GP will advise you.

NSAIDs start working within a few hours. The effects of some will only last for a few hours but others are effective all day. Your doctor will help you to find the best formula and dose for you. There are now about 20 different NSAIDs and coxibs available. Some, such as aspirin and ibuprofen are widely available over the counter and are described in the sections that follow. Others, such as naproxen and the coxibs, are only available on prescription.

There are concerns that all simple painkillers may slightly increase the risk of cardiovascular disease and kidney disease. You should discuss this with your doctor if you are concerned. You should not take NSAIDs if you are taking blood thinning medications such as warfarin.

For more information see Arthritis Ireland’s drug leaflet on NSAIDs.

Aspirin

Aspirin is widely used as a painkiller for mild to moderate pain. It can reduce fever and has an anti-inflammatory effect. It is available over the counter in 300 mg tablets and is usually taken in doses of 300–600 mg four times a day after food.

Aspirin can cause stomach-related side-effects at higher doses. Soluble forms reduce this risk to some extent, as do enteric-coated tablets (which have a coating to make sure the drug is not absorbed into the body until it reaches the small intestine), but you should not take it if you have indigestion, heartburn or a history of stomach ulcers. It can cause serious bleeding in the digestive system, particularly if you drink alcohol, take the blood-thinning drug warfarin or are over 60. For this reason many doctors will now advise you not to take aspirin for pain relief, but to take an NSAID or a coxib instead. You should not use fish oil if you are taking aspirin because they can interact.

In some people, aspirin can make asthma worse or cause an allergic reaction that results in rashes and hives. If you experience any of these side-effects you must stop taking aspirin immediately. Children and young people under the age of 16 should not take aspirin.

Aspirin is also used in low doses to reduce the risk of strokes and heart attacks. This dose does not have a pain-relieving effect. If you are on long-term, low-dose aspirin you must be careful about taking other NSAIDs because it increases the risk of stomach bleeding. Ask your doctor's advice if you are unsure.

Ibuprofen

Ibuprofen is a widely used painkiller and anti-inflammatory. It is available over the counter in doses of 200–400 mg and can be taken up to four times a day after food.

Stronger and slow-release NSAIDs are available on prescription and can be used for rheumatoid arthritis and other types of inflammatory arthritis. You should not take more than one type of NSAID tablet at a time. NSAIDS can have serious side-effects and should not be used long-term. Speak to your doctor if you need longer term pain relief.

NSAID gels and creams

A number of NSAIDs are also available as gels or creams, which you apply directly to the affected area if the pain is localised. Some of these (e.g. ibuprofen, diclofenac) are available over the counter while others (e.g. ketoprofen) are only available on prescription. NSAID gels may be a good option if NSAID tablets tend to upset your stomach. Some of the drug is still absorbed into the bloodstream so be careful not to use too much gel, particularly if you are also taking NSAID or coxib tablets, as this may increase the chance of side-effects.

For more information see Arthritis Ireland’s drug leaflet on NSAIDs: https://arthritisireland.eu.rit.org.uk/nsaids

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Compound analgesics

Compound analgesics are made from a combination of two different drugs. The most commonly used drugs in compound analgesics are paracetamol, aspirin, codeine or dihydrocodeine. Some common compounds are listed in Table 2.

These drugs are most commonly used because they cause few severe side-effects. Some compound analgesics containing low doses of codeine are available over the counter, but other stronger ones are only available on prescription. Ask your doctor’s advice if you are pregnant or breastfeeding. Older people may be advised to reduce the maximum dose.

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Opioid analgesics

Opioid analgesics can be more effective for pain relief than simple non-opioid analgesics, so they are used for moderate to severe pain. Pain is considered to be severe if it is disabling, meaning you have to take more frequent rests or can only walk or move awkwardly.

Opioid analgesics can cause more side-effects than simple analgesics and can lead to dependency and addiction, so they are only available on prescription and you will be monitored more closely by your doctor. They are only used if other analgesics have not worked. In many cases they are used for short periods of time or alongside other painkillers when necessary – this is to reduce the risk of side-effects and dependency. All side-effects are more common in older people, so the dose may be reduced.

The most common side-effects with opioid painkillers are:

  • nausea and vomiting (some people are more prone to this than others but it often settles with time)
  • constipation
  • drowsiness and dizziness, which is increased when combined with alcohol – be careful when driving and using electrical equipment
  • reduced concentration or confusion
  • reduced ability to breathe (respiratory depression) – make sure the doctor prescribing the drug knows if you have long-term breathing problems like chronic obstructive pulmonary disease (COPD) or asthma.

If you experience any side-effects, talk to your doctor.

Opioid analgesics come in a tablet or patch. Your doctor will advise on which type is best for you depending on the severity of your pain, your age and any other medication that you are taking.

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Which medications can help with osteoarthritis?

If you have osteoarthritis you will probably experience pain at times, so you should use painkillers when it is interfering with your everyday life. Some people with osteoarthritis will find that the pain is more constant, making day-to-day activities difficult, affecting concentration and disturbing sleep. If your pain affects you in these ways you may need to take combinations of medications. Taking combinations can also often help if you have back or neck pain.

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Which medications can help with inflammatory arthritis?

If you have inflammatory arthritis, such as rheumatoid, psoriatic arthritis, or ankylosing spondylitis then you will need to take a combination of drugs. NSAIDs (including coxibs) are more effective than analgesics in relieving the pain and stiffness of inflammatory arthritis. However, you may also be prescribed other drugs that act to reduce inflammation caused by the disease – these include disease-modifying anti-rheumatic drugs (DMARDs) and steroids. By reducing inflammation, these will help with the pain even though they are not themselves painkillers. They also help with swelling and stiffness and reduce the risk of longer-term damage to the joints.

Your rheumatologist may prescribe one or more DMARDs such as methotrexate and biological therapies. These drugs may take several weeks to reduce inflammation, so you may still have pain to begin with. It is usually fine to take painkillers and/or NSAIDs (unless your doctor advises otherwise) if you need to. Once the DMARDs start to work you may be able to reduce your painkillers or NSAIDs. If you are prescribed a DMARD or biological therapy you should read the appropriate Arthritis Ireland leaflet on the specific drug(s). 

Steroids can be given in tablet form, or by injection either into a muscle or directly into a joint. They usually have a more rapid effect than DMARDs. However, they are not suitable for use as regular painkillers because of their side-effects.

Other types of arthritis also cause pain but require treatments that are more specific, for example NSAIDs are very effective in gout whereas analgesics are not. You should speak to your doctor if you are unsure.

See Arthritis Ireland’s leaflets on Local steroid injections and Steroid tablets.

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What medications are used in nerve (neuropathic) pain?

Nerve pain can be caused by damage to nerves or nerve endings. This causes the nerves to send pain signals to the spinal cord spontaneously, without needing a specific stimulus, or in response to something that would not normally hurt, such as gentle stroking of the skin. This sometimes happens in complications from diabetes and in some people with sciatica and complex regional pain syndrome (reflex sympathetic dystrophy), as well as rheumatoid arthritis.

Pain from nerve damage can be very severe and troublesome, for example the pain that is caused by spinal problems or that follows a bout of shingles. This pain may respond to stronger opioids but occasionally other drugs are used. Drugs used to treat nerve damage can include amitriptyline, gabapentin, pregabalin and duloxetine.

Amitriptyline

Amitriptyline is an antidepressant drug but at lower doses is widely used to relieve chronic (long-term) pain associated with arthritis, nerve pain or fibromyalgia. Because it has a sedative effect it is best taken about two hours before going to bed. Amitriptyline causes drowsiness and a dry mouth and some people cannot tolerate even low doses. You should not take amitriptyline if you have certain forms of glaucoma or heart rhythm problems.

Gabapentin, pregabalin and duloxetine

Gabapentin, pregabalin and duloxetine are also drugs which can be effective for nerve pain. Like amitriptyline, they may be given in combination with other pain medications in the most troublesome nerve pain conditions. Duloxetine is licensed for pain from nerve damage resulting from diabetes, which most often starts in the feet. The most common side-effects are sleepiness, dizziness and weight gain.

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What if I have problems with my heart?

If you have a serious heart condition, high blood pressure or uncontrolled high cholesterol, or if you are in severe cardiac failure or have just had a heart attack, your doctor may advise you not to take some painkillers, or recommend that you do not take them very often. This is because there is evidence of a slight but important risk of future cardiovascular problems. This risk must be weighed carefully against the benefit you get from these drugs, which may be more effective than simple or compound analgesics if you have inflammatory arthritis.

Coxibs are generally best avoided if you have cardiovascular disease, but may be an option if you have a peptic ulcer and cannot tolerate NSAIDs combined with a proton pump inhibitor.

All NSAIDs are linked to a small increase in the risk of having a heart attack or stroke. This includes NSAIDs bought over the counter, such as ibuprofen.

You should always read the patient information leaflet included with your medicines package to keep you informed about any possible side effects of your prescribed medications.

Table 1: Common examples of analgesics

Pain level Mild Moderate Severe

Simple non-opioid analgesics

e.g. paracetamol, aspirin, ibuprofen

Compound analgesics

e.g.co-codamol, co-codaprin, co-dydramol

Opioid analgesics

e.g. codeine, tramadol, morphine
What are they? The most common form of analgesic, also including non-steroidal anti-inflammatory drugs (NSAIDs) A combination of drugs in one tablet, usually including paracetamol, aspirin, codeine or dihydrocodeine The strongest types of painkiller
What are they used for? Mild to moderate pain, for example headaches, injuries and osteoarthritis, or as an addition to stronger painkillers Mild to moderate pain, for example injuries and osteoarthritis, or as an addition to NSAIDs Moderate to severe pain caused by osteoarthritis, or as an addition to NSAIDs for severe pain
Where do I get them? Over the counter at supermarkets and chemists, although some NSAIDs are only available on prescription Milder forms are available over the counter, but stronger types are only available on prescription Most are only available on prescription
What are the common side-effects?

Paracetamol has few side-effects with short-term use. Caution may be needed with long-term use because of possibility of side-effects on the cardiovascular system and kidneys.

NSAIDs have a number of side-effects, particularly on the stomach, cardiovascular system and kidneys

Compounds made from codeine and dihydrocodeine can cause constipation, nausea and loss of concentration

Nausea and vomiting, constipation, drowsiness and dizziness
What else should I know?

Should not be used at high doses for long-term pain

Paracetamol and some NSAIDs are available as suppositories
Can be used instead of NSAIDs if these can’t be taken for any reason Can cause more side-effects compared with non-opioid types

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Table 2: Common examples of compound analgesics

Co-codamol Co-codaprin

Co-dydramol

What is it? Codeine (8 mg) and paracetamol (500 mg) Codeine (8 mg) and aspirin (400 mg)

Dihydrocodeine (10 mg) and paracetamol (500 mg)

What dose can I take? Up to two tablets four times a day Up to two tablets four times a day with food

Up to two tablets four times a day

Where do I get them? Over the counter or on prescription

On prescription

On prescription
What are the common side-effects?

Constipation, nausea,   drowsiness and dizziness

Caution needed with long-term use because of possible side-effects of paracetamol on the cardiovascular system and kidneys
Constipation, nausea, drowsiness, dizziness, heartburn and indigestion Constipation, nausea, drowsiness and dizziness
What else should I know? For more severe pain, combinations of 15 mg/500 mg and 30 mg/500 mg are available For more severe pain, combinations of 20 mg/500 mg and 30 mg/500 mg are available

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