Pain relief medications - what are the risks and what are the benefits?

Pain relief medications and anti-inflammatories have become more easily available - supermarkets have allowed more types to be purchased directly (over-the-counter), and prescription pain relief manufacturers are also coming up with new options your doctor might prescribe.

Their widespread use means safety of the available products is carefully looked at, and this means few weeks go by without the results of a study appearing in the newspaper or on TV. Usually, the concerns centre on the possible aggravation of asthma, stomach bleeding risks or cardiovascular (heart and stroke) risks.

Most people use pain relief only occasionally, but others who need it constantly may have questions about safety. Dr John Petrie, a consultant rheumatologist and pain specialist in Rotorua, has taken time to answer some of the common questions that may have arisen following recently reported studies.

What are the main types of pain relievers?

The pain relievers commonly available without prescription are aspirin, paracetamol, ibuprofen and codeine - and these are combined in some products. Commonly prescribed pain relievers include examples of a group of anti-inflammatories called NSAIDs - non-steroidal anti-inflammatory drugs - as well as steroidal medications (eg, prednisone), opioid analgesics (eg, codeine, morphine) and other types (eg, tramadol).

NSAIDs include commonly used medications like aspirin and ibuprofen, and diclofenac and naproxen.

What are the differences?

There are pain relievers that simply relieve pain - analgesics. And there are pain relievers that act by reducing inflammation - anti-inflammatories (see Table below).

Analgesics work by reducing the pain signals at the level of the nerves and brain.

Anti-inflammatories work by blocking the cyclo-oxygenase (COX) enzymes, thereby reducing inflammatory pain. These enzymes are important in the body's inflammation reaction (COX 2 enzyme), but also in maintaining the protective lining of the stomach (COX 1 enzyme). Older NSAIDs block both types of COX enzyme. Newer COX 2 inhibitors block just the inflammation pathway and not the stomach's COX 1 enzyme.

Steroids also reduce swelling and inflammation.

Commonly used types of pain relief medication (New Zealand, February 2010)

Which pain relievers are good for certain causes of pain?

Pain following injury, such as sprains and strains, can often be helped with over-the-counter NSAIDs such as ibuprofen. Pain from the inflammation of arthritis is usually best helped by NSAIDs, although the over-the-counter preparations of ibuprofen or aspirin may not be strong enough and you will require a prescription from the doctor.

Non-inflammation pains, such as headache, may be best helped with paracetamol, and paracetamol can often be helpful in people with longstanding pain from neck or back trouble.  Many people with long term arthritis find paracetamol helpful in addition to NSAIDs.

Aspirin

What are the main benefits of aspirin?

Aspirin is easily available over-the-counter and is rapidly absorbed when taken by mouth. Many people find this the most effective treatment for arthritis pain. 

What are the main risks of aspirin?

Aspirin is the most likely of all the NSAIDs to give indigestion or stomach ulcers. It can also interfere with a number of other medicines, and may lead to easy bruising from blood thinning. It should not be used in combination with other NSAIDs, such as ibuprofen or those prescribed by a doctor, unless it is being used in low dose to prevent the recurrence of a heart attack or stroke.

Paracetamol

What are the main benefits of paracetamol?

Paracetamol is a very helpful pain reliever for many types of pain that are not directly caused by inflammation. Neck pain, back pain and headache are often helped by paracetamol, and it has the advantage of avoiding any of the stomach side effects associated with other medications. It will not affect the kidneys.

What are the main risks of paracetamol?

The main risks of taking paracetamol are to the liver, if taken in overdose. An excess of paracetamol can cause severe liver damage. Accidental overdose is a risk because many different products contain paracetamol, so if taking more than one medication make sure you check the label for ingredients.

NSAIDs

What are the main benefits of NSAIDs?

NSAIDs are most effective in people with inflammatory pain. This includes almost any form of arthritis (including gout), period pain and injuries such as sprains or strains. Some people find one form of NSAID more effective than another so it is worthwhile trying different ones to find the one that is best for you. NSAIDs usually require a prescription, although some are available over-the-counter in smaller doses (eg, ibuprofen, diclofenac).

What are the main risks of NSAIDs?

The main risks of taking NSAIDs include increases in blood pressure or ankle swelling in people who are susceptible, and gastrointestinal problems such as indigestion and nausea. There is a small but identifiable increase in the risk of stomach ulcers. Most people, however, find they tolerate NSAIDs well with good relief of their pain.

Ibuprofen

What are the main benefits of ibuprofen?

Ibuprofen is one of the milder NSAIDs and is easily available over-the-counter without prescription. It is quickly absorbed into the bloodstream and offers good relief for sprains, strains and mild inflammatory arthritis. It is also relatively inexpensive.

What are the main risks of ibuprofen?

As with any NSAID, ibuprofen can cause asthma in people who are sensitive to it. It has been associated with kidney trouble and people who are on diuretics or other blood pressure medication should be careful about taking ibuprofen without medical advice. If you are already taking an NSAID on prescription from your doctor you should not combine this with over-the-counter ibuprofen.

COX 2 inhibitors

What are the main benefits of COX-2 inhibitors?

As with regular NSAIDs, COX-2 inhibitor drugs predictably reduce the pain and stiffness associated with inflammatory arthritis and can be useful in other forms of inflammatory pain. Their advantage over the NSAIDs is that they have been shown to have much lesser effect on the stomach.

What are the main risks of COX-2 inhibitors?

The COX-2 inhibitors can still affect the kidneys and blood pressure, and so caution must be taken when using them with other medications.

Steroids

What are the main benefits of steroids?

Steroids can be given either by injection for painful inflammation such as arthritis or tendinitis, or by mouth. They are indicated only for people with significant inflammation as the cause of their pain, as steroids are very potent anti-inflammatories, but they do not have any other analgesic or pain relieving effect.

What are the main risks of steroids?

Side effects of steroids are often a cause of concern, but if used in small doses for the appropriate reason, side effects such as weight gain, thinning of the skin and easy bruising can be limited. It is important though that steroids be used only in situations where the inflammation requires the use of these potent drugs.

Opioids

What are the main benefits of opioids?

Opioids are very effective drugs for the management of severe pain. 

What are the main risks of opioids?

All opioids, however, have potential long term addiction problems, and may cause problems of drowsiness and constipation. Once people with chronic pain have started on opioids it can be very difficult to come off them without withdrawal effects.

What can I do to make sure I'm taking my pain reliever safely and effectively?

In general, advice given by your prescribing doctor, or on the packaging of over-the-counter medications, can be relied upon to reduce the risks associated with taking these medications. It is important to recognise that the risks are small, and do not pose a threat to everyone who uses these forms of pain relief. The benefits can only be attested to by the sufferer who finds relief with the use of any of the above medications.

Original material provided by everybody, contributed to and reviewed in April 2007 by Dr John Petrie.