Put down the paracetamol, it’s just a placebo for low back pain

Up to 90% of the population will experience lower back pain over their life time; around 25% will have it on any given day. Flickr: Christian Bucad, CC BY-NC-ND

People with lower back pain are usually told to take some paracetamol for relief. But research published today shows that this almost universal advice is misguided.

Up to 90% of the population will experience lower back pain over their life time; around 25% will have it on any given day.

“Non-specific low back pain” - so called because it’s not caused by a serious condition, such as a fracture, cancer or infection - accounts for around 95% of all cases. It includes people with so-called slipped discs, spinal misalignment, facet joint problems, spinal instability and, in some cases, back pain radiating into the leg.

In research published in The Lancet today, we show that paracetamol doesn’t speed recovery, or reduce pain for people with lower back pain any more than a placebo does. Our results raise questions about the value of pain medications for managing low back pain.

What we did

Paracetamol is universally recommended in treatment guidelines for treating non-specific low back pain. But this recommendation isn’t actually based on direct evidence of benefit; it’s just been compared to other medicines and is preferred because it’s a safe pain killer with few, if any, side effects. And because it was assumed to help.

In a study involving 1,643 people with lower back pain, we directly tested paracetamol against placebo and also compared two ways of taking it - regularly and intermittently. Many people do the latter, following advice of taking paracetamol “as needed”. We thought they would need to take it regularly to benefit.

All our subjects took their respective medicine for up to four weeks. And all of them were also given general advice and reassured that they would recover.

We followed them all up for three months, and found both methods of taking paracetamol (regularly and intermittently) were completely ineffective. What’s more, we found that people did just as well taking a sugar pill (our placebo) as taking paracetamol for lower back pain.

It’s clearly time to reconsider the recommendation for taking this drug and more generally, the contribution of pain-relief medicines in helping people manage acute lower back pain.

Paracetamol is universally suggested in treatment guidelines for treating non-specific lower back pain, but there is no direct evidence to support this recommendation. Flickr: Leach84, CC BY-NC-SA

What this means

So, what do our results mean for managing lower back pain, and what, if anything, should people do instead of taking paracetamol?

First, if you haven’t started any treatment and are deciding what to do about about your lower back pain, our study shows paracetamol will neither help you recover quicker or dull your pain. So, there’s no point in taking it and no justification for your doctor to recommend it.

Second, if you are taking paracetamol for acute lower back pain and feel it’s helping, you should continue to take it. But if your pain doesn’t improve after a week or two, we suggest you see a doctor about it.

What our results don’t suggest is that it’s better to take other pain killers instead of paracetamol. It’s important to remember that the purpose of taking pain-relief medicine for lower back pain is so people can stay as active as possible. If you take very strong pain medication, it can make you sleepy and drowsy, and it could limit what you’re able to do.

You will recover

What’s more, we actually have a very poor understanding of the benefits and harms of most of the pain medicines commonly used for acute back pain.

Two key examples are non-steroidal anti-inflammatory drugs and opioid analgesics. We simply don’t have large, well-conducted trials (like our study) that have tested these medicines so people with lower back pain and their doctors can make informed decisions about the balance of benefits and harms.

It’s not all bad news though. People with low back pain are usually told to maintain normal activity as much as possible, avoid bed rest and reassured that they’re likely to recover. And that’s exactly what happened in our study.

We provided this advice and reassurance to all our subjects and the vast majority of them recovered relatively quickly (about half recovered within two and a half weeks). These key messages need to be reinforced.

So, don’t be concerned if your doctor doesn’t prescribe medication for your back pain. It’s best to focus on the advice you’re given rather than a script for medication.