Nerve drug pregabalin ineffective for sciatica, study shows

The nerve pain drug pregabalin is not an effective treatment for sciatica and is associated with a significant number of side effects, researchers have concluded.

The Australian research team carrying out the study says that while it is difficult to know how many patients with sciatica are prescribed the drug, its use is growing year on year.

Previous research looking at pregabalin in sciatica had been inconclusive, so the team carried out an eight-week, double-blind, randomised controlled trial in just over 200 patients.

After the two-month study, there was no difference in leg pain as measured on a ten-point scale in patients who had taken the drug or placebo, the researchers report in The New England Journal of Medicine
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(online, 23 March 2017).

Over one year of follow-up, the researchers also assessed extent of disability, back-pain intensity and quality-of-life measures and found no difference between the two groups.

But 227 adverse events were reported by patients taking pregabalin compared with 124 in the placebo group, with dizziness being the most common complaint.

Those taking part had been suffering from at least moderate pain from sciatica from between one week and one year before starting the trial.

Study leader Christine Lin, senior research fellow in medicine at The George Institute for Global Health, University of Sydney, says sciatica is commonly caused by the irritation of nerve routes in the lower back.

She adds that while pregabalin had shown to be effective in other nerve pain conditions, she wasn’t completely surprised that it was ineffective in sciatica because other evidence to date had been unconvincing.

“Taking pregabalin is no better than taking placebo in patients with sciatica, but will likely give patients more side effects, for example dizziness. Based on that, we do not recommend the use of pregabalin in people with sciatica,” she says.

Lin adds: “Unfortunately, it is not exactly clear what helps people with sciatica. We have no clear evidence that medicines such as anti-inflammatories, oral steroids and opioids are effective for sciatica. Corticosteroid injections have a small and short-term treatment effect.”

But she says most patients with sciatica do improve even though the pain can initially be quite severe.

“It is important that the patients are reassured of the fact that sciatica will get better with time.

“Patients should also be advised to stay as active as possible and to avoid prolonged bed rest.”

Lin also says that anyone taking pregabalin for sciatica should not stop taking it but see their doctor for advice because they may need to come off gradually.

Roger Knaggs, associate professor in clinical pharmacy practice at the University of Nottingham and an expert in pain management, says the results are disappointing for patients with acute sciatica but not surprising.

He echoes Lin’s advice that many symptoms will resolve, usually over 8–12 weeks, and that patients should keep active.

“All medicines should be used to promote activity and it is clear that side effects for patients taking pregabalin in this study were a major barrier to this.”