A recent Hopkins study has found that when treating lower back and leg pain, standard steroid injections tend to outperform the emerging treatment using anti-inflammatory pain medicine injections.
Lower back pain contributes a significant portion annually — close to $100 million — to health care costs in the United States. The most common cause is herniated disc, which can result in compressed nerves and the release of pro-inflammatory molecules. Tumor necrosis factors, or TNFs, form one group of these molecules.
TNFs are secreted by cells of the immune system to prevent the creation of tumors and the replication of viruses in the body. It causes several defense responses, including the inflammation experienced by patients with sciatica, which is pain the lower back and leg.
Etanercept is a genetically engineered compound that acts to inhibit the inflammatory effect of TNFs. Current standard treatment for sciatica involves the injection of epidural steroids. However, recent studies have shown that the method of injection of these steroids can cause adverse effects. As lead author Steven P. Cohen wrote in an e-mail to The News-Letter, “Epidural steroid injections are very safe, but when they’re given by the transforaminal route — which is more effective than the conventional interlaminar route — there is a risk for catastrophic neurological complications, especially in the neck.”
Cohen’s group is the first to directly compare the therapeutic effects of the two methods. Their study, published in the most recent edition of Annals of Internal Medicine, was performed over the course of three years and involved patients who had been experiencing sciatica for less than six months.
The treatments were administered via two injections separated by two weeks. Pain measurements were taken before treatment, and again one month after the injections had been given. The results showed that leg and back pain improved for all treatment groups: etanercept, steroids, and a saline placebo used as a control.
However, for overall functional capacity, sizable improvements were reported only for steroid and saline-treated patients, with no marked change in patients of the etanercept group.
After the one month follow-up, the researchers continued their study with patients who had a significant positive outcome. Further measurements were taken at three and six months. Overall, about half of the patients in the study were able to reduce the levels of painkillers being administered after they experienced pain relief. Of those with decreased painkiller administration, there was a higher percentage of steroid-treated patients than etanercept patients.
These follow-ups showed that even though steroid injections resulted in higher initial pain relief compared to those treated with etanercept, steroid patients felt a resurgence of pain later on. The group postulated that the most probable explanation for this phenomenon is that the pain-reliving effect of steroids are fast-acting but short-lived. Another possibility is that all the treatments have similar efficacy, but the effects of the steroids were simply realized earlier.
One limitation of the study was that the researchers used a relatively low dose of etanercept for treating patients of that group. They choose this etanercept dose because a previous study on animals and human patients showed it was both safe and effective when administered epidurally.
Despite the limitation, the low dosage has its benefits. “One of the advantages of epidural or regional drug administration is that you can reduce the dose of some medications significantly, so that the side effects are less prominent,” Cohen wrote.
The study also did not administer treatments as-needed by patients, but according to the study’s designated treatment times. Cohen explained this is mainly due to the experimental method. “This highlights the difference between efficacy and effectiveness. The latter term is more relevant for clinical practice, and hence studies that seek to determine effectiveness should strongly consider performing treatments on an ‘as needed’ basis. But we needed to first establish efficacy, which requires a more rigid structure and selection criteria,” Cohen wrote.
The future of pain medication lies in tailoring treatment based on the genetic background of the patient to provide the safest and most effective form of treatment. The type of pain investigated in this study can have both neurological and non-neurological implications.
“Someday, we may be able to tailor treatments based on somebody’s genes. But we’re not there yet, so all we have to go by is phenotype,” Cohen wrote.
