The perils of pain relief

Painkillers are harmless if the right medicine is taken at the right dose. Photo / Thinkstock.

Grab a glass of water, wash a few pills down, and in minutes your headache/toothache/period pain/fever has all but vanished. What's more, they're relatively affordable and widely available. And hangovers would be at least 10 times worse without them. What could be simpler?

It's undeniable that painkillers can be a godsend in times of need. However, it's little known they can also have a rather dark side. Too much aspirin and ibuprofen, for example, can cause stomach ulcers and bleeding; paracetamol can cause damage to the liver; and opiate painkillers - again, if taken in excess - can lead to such undesirable symptoms as anxiety, constipation, agitation and depression.

But fret not, because you needn't avoid painkillers altogether. "The potential [of painkillers] to cause harm is reduced by using the right medicine at the right dose, to give the best effect," says ProCare clinical director John Cameron. "In medicine, we're constantly balancing risk versus benefit."

Don't take more than the packet advises, he warns. "More is not necessarily better, and can often be harmful. Even over-the-counter medicines such as aspirin and paracetamol are dangerous and potentially lethal in overdose. "So if your pain is not being eased by the prescribed dose, don't up it."

On the other hand, "We find people have popped a couple of paracetamol and then complain they aren't working," he says. "Even though they should [actually] be taking two tablets every four hours because two 500mg tabs every four hours is the correct dose. One [tablet] twice a day won't do much."

Overall, as long as you take the stated dose, the amount of time (days, weeks, etc) you are taking the painkiller is not of huge importance, he says.

One time it does pay to be cautious is when taking prescribed and over-the-counter medicines together. This is because over-the-counter medicines will also contain the pain relievers you are being prescribed. "Always read the label, and check with your pharmacist or practice team," Dr Cameron says.

Inversely, ibuprofen and paracetamol can be used together, because they use different pathways to treat pain and fever. Take Paracetamol every four hours, with ibuprofen added to every second dose of paracetamol.

Painkiller addiction, can occur either psychologically or physically. "Psychologically, painkillers can be habit forming, where the patient is scared that if they don't take the meds, their pain might hit," says Dr Cameron. "This is best dealt with by gentle reduction or alternative therapies such as behavioural therapy, exercise, and so on."

Physical addiction is most common with the codeine or opiate-containing medicines. Usually, if the drug is being balanced by the pain, the risk of addiction is low, Dr Cameron says. "It's important to deal with concerns and fears around these matters when they are prescribed so, as long you get good information about the use of your painkillers, you can make accurate choices."

It's a common belief that people develop a resistance to painkillers, however this is not the case. Rather, the nature of a pain will often change, leading to the need for changing what is taken. And, "sometimes there's an unrealistic expectation that pain relievers will remove all pain. This isn't easily obtained unless we put the patient to sleep. So if what you are taking is the advised dose and it doesn't seem to give you the relief you need, perhaps we need to adjust your medicine. Remember, more is not necessarily better."

Children can use the same range of painkillers as adults, with paracetamol often the first port of call. Again it's important to follow dosage recommendations, and be sure to check the strength of the painkiller itself. Aspirin in children under 13 is avoided due to the potential risk of Reye's Syndrome (an extremely rare but serious illness that mainly affects children and can harm the brain and liver).

Older people are more likely to simultaneously need pain relief and be on additional medications, so it can be trickier to get the balance right, says Dr Cameron. "There is a higher risk of gastrointestinal side effects such as stomach irritation or ulcers on anti-inflammatories with the elderly, so we generally warn our patients what they should be watching out for. We weigh up the risk-versus-benefit equation."

A rule of thumb for everyone, he says, is to use pain relievers with the right expectations, and with good information. "Doctors, nurses and pharmacists are great resources, so if you don't know or are worried, ask for information."