(HealthDay)—Spinal steroid injections—the type involved in the current fungal meningitis outbreak in the United States—provide only short-term relief for sciatica-related leg and back pain, according to a new analysis.
Sciatica, a common type of low back pain, is characterized by intense pain shooting down one leg, along with tingling and numbness, as a result of injury or pressure on the sciatic nerve.
Epidural steroid treatments—injections into the joint spaces of the spine—have been used to treat back pain for a half-century, but consistent guidelines for their use are nonexistent, according to the new study, which was published Nov. 13 in the journal Annals of Internal Medicine.
In the new analysis, researchers analyzed 23 clinical trials involving more than 3,100 patients; the trials compared steroid injections to other treatments. Researchers had followed patients for a year or longer, gauging pain relief at various points.
"The review showed that [epidural injections] offered only small, short-term improvement in pain and disability for people with sciatica and had no long-term effect," said study co-author Dr. Chris Maher, professor of physiotherapy at the School of Public Health at the University of Sydney in Australia.
At two weeks and three months after treatment, 10 trials showed leg-pain relief and 14 reported improvements in disability. But after a year or more, no differences were found in leg pain, back pain or disability for those given injections compared to those given a placebo.
"Given that the treatment effect is likely to be small and short term, patients with sciatica should discuss the potential risks involved in [steroid injections] with their doctor before agreeing to the procedure," said Maher, who also is director of the George Institute for Global Health, in Sydney.
The results echo some of the findings of another study, published earlier this year, that concluded that after six months, epidural steroid injections were no better than the anti-inflammatory drug Enbrel (etanercept) or an injection of anesthetic and saline.
Dr. Steven Cohen, professor of anesthesiology and critical care medicine at Johns Hopkins School of Medicine in Baltimore and director of pain research at Walter Reed National Military Medical Center, said the findings shouldn't rule out use of epidural steroid treatment.
"It is likely that, at least in some people, epidurals may decrease the likelihood that they will need surgery—not because they last so long, but because they decrease pain enough for your body to heal itself and/or prevent those deleterious changes from occurring in the nervous system," Cohen said.
Cohen was a researcher on the study comparing the injections with Enbrel, which was published in April in the Annals of Internal Medicine.
Many factors play into the injections' effectiveness, he said. One is the duration of pain. The longer a patient has had the pain, the less responsive treatment tends to be, not only to injections but also to other therapies.
Risks to patients were not examined, Maher said. These remain a concern, especially since tainted steroid injections have killed 32 people and sickened 438 to date since the fungal meningitis outbreak came to light in September. The contaminated drugs were traced to a compounding pharmacy—now shut down—that produced drugs to meet the needs of specific patients. Such specialty pharmacies are regulated by state boards, not the U.S. Food and Drug Administration.
Despite that outbreak, epidural injections for back pain are extremely safe, Cohen said, and ''certainly safer than commonly used alternatives such as surgery or narcotics."
"When you examine alternatives for sciatica, no treatment is very reliable or effective," he said, adding that doctors should be more selective in choosing which patients could benefit from the injections.
Dr. Roger Chou, associate professor of internal medicine at Oregon Health & Science University, in Portland, agreed.
"[This new review] underscores the importance of performing epidural steroid injections judiciously, in patients who have clear indications for it, especially in light of the fungal meningitis outbreak," Chou said. There is no evidence that the injections work, for instance, in those with low back pain without sciatica.
Explore further: Etanercept - genetically engineered compound for back pain - falls short: study
To learn more about sciatica, visit the U.S. National Institutes of Health.