A commonly prescribed painkiller for sciatica nerve pain has been found no better at providing relief than a placebo in a study by Australian researchers.

People suffering from sciatica nerve pain spreading down their legs aren't necessarily any better off if they take a commonly prescribed painkiller, a study has found.

Researchers from the Sydney-based George Institute for Global Health gave 209 people with moderate-to-severe sciatica either the painkiller pregabalin or a placebo and found little difference between the relief they delivered.

Associate professor Christine Lin, who led the study, said the study was sparked by concerns that people with sciatica were being over-prescribed painkillers.

Sciatica is characterised by leg pain, including tingling, numbness or weakness, that radiates from the lower back and down the sciatic nerve that runs along the back of each leg.

People with lower back problems such as herniated discs or spinal stenosis can often have symptoms of sciatica.

Assoc prof Lin said the use of neuropathic pain medicines such as pregabalin had increased six fold in the past decade, while an estimated 200,000 to 400,000 Australians are thought to be affected by sciatica each year.

"But, until now there has been no high quality evidence to help patients and doctors know whether pregabalin works for treating sciatica," she said on Thursday.

"Our results have shown pregabalin treatment did not relieve the pain, but did cause side effects such as dizziness."

For the study, 108 people were given up to 600mg of pregabalin a day while the remaining 101 received a matching placebo.

After eight weeks, both sets of people reported similar levels of pain in their legs.

The results were also similar after 52 weeks.

However the people who took the pregabalin reported nearly twice as many adverse side effects, the most common being dizziness.

Despite the findings, almost two thirds of the patients in each group reported being extremely satisfied or satisfied with their treatment.

Assoc Prof Lin said two years after pregabalin was listed on the Pharmaceutical Benefits Scheme in 2013, prescriptions soared to higher-than-expected 2.4 million.

She said the most important thing people with sciatica could do is avoid bed rest and keep active.

"Unfortunately there are no drugs proven to work for people with sciatica and even epidural injections only provide a small benefit in the short term," Assoc prof Lin said.

"What we do know is that most people with sciatica do eventually recover with time."