A new study suggests that injections of steroids or arthritis drugs in the spine may not provide much extra relief for people with chronic back and leg pain due to nerve damage.
The drug injections also didn’t increase the risk of infection and other complications, despite some previous safety concerns.
It’s possible, researchers said, that higher doses of steroids or the anti-arthritis drug etanercept (marketed as Enbrel) may do a better job of easing pain in this notoriously hard-to-treat group of patients. Or people might get more pain relief if the shots are given as-needed, instead of at set intervals.
So the findings can’t say definitively whether or not either type of injection might help some people with nerve-related chronic pain, researchers report in the Annals of Internal Medicine.
“This kind of pain is very challenging to treat. There’s no reliable treatment that works in everyone,” said Dr. Steven Cohen from the Johns Hopkins University School of Medicine in Baltimore, who worked on the study.
Medications tend not to work very well, he told Reuters Health. And although surgery may help in the short term, studies haven’t found an effect in people who did or didn’t have an operation a couple of years down the line.
Most people with lower back and leg pain due to nerve damage - also known as sciatica - are treated with epidural steroid injections, Cohen said. But recently, there’s been more interest in injections of immune-suppressing drugs like etanercept.
What Is ENBREL?
ENBREL is a prescription medicine that can be self-injected. It is used to treat five long-term inflammatory diseases: moderate to severe rheumatoid arthritis (RA), moderate to severe plaque psoriasis, psoriatic arthritis, moderate to severe juvenile idiopathic arthritis (JIA), and ankylosing spondylitis (AS).
ENBREL is grouped within a class of medications called biologic response modifiers, or biologics. By working on the immune system, biologics block proteins that contribute to the disease process. Because ENBREL suppresses the immune system, patients are at a greater risk for getting serious infections.
The science behind ENBREL
Tumor necrosis factor (TNF) is a substance made by your body’s immune system. People with inflammatory diseases such as rheumatoid arthritis, plaque psoriasis, psoriatic arthritis, juvenile idiopathic arthritis, and ankylosing spondylitis have too much TNF in their bodies. ENBREL reduces levels of the active form of TNF.
“People are looking for something more effective and something safer,” he said.
“The findings are disappointing, but by no means is this the end of the story.”
LACK OF EFFECT FOR EXPENSIVE DRUGS
Cohen’s study involved 81 people who’d had sciatica for at least a month. The patients were in their early 40s, on average, and treated at one of four military medical centers and two civilian hospitals.
Study participants were split into three treatment groups. They were given two spinal injections, two weeks apart, of the steroid methylprednisolone, etanercept, or normal salty water, called saline. Neither the patients themselves nor the doctors treating them knew who got which type of injection.
Sciatica commonly describes the symptoms of pain and possibly numbness or weakness that radiate along the sciatic nerve and tend to be felt in the rear, down the back of the leg and possibly to the foot. Sciatica is one of the most common forms of pain caused by compression of the spinal nerves in the lower back, and the leg pain is usually much worse than the back pain.
The sciatic nerve is the largest single nerve in the human body; it runs from each side of the lower spine through deep in the rear and back of the thigh and all the way down to the foot, connecting the spinal cord with the leg and foot muscles.
The sciatica symptoms one feels (nerve pain, numbness, tingling, weakness) tend to be different depending on where the pressure on the sciatic nerve occurs. The patient’s pain and specific sciatica symptoms can usually be traced to where the injured/irritated nerve originates in the lower back.
At check-ins one month later, patients’ back and leg pain was reduced by a similar amount, regardless of which treatment they’d received. Their back pain scores fell by average of one to two points, and leg pain by two to four points, on a 10-point scale.
People who had gotten steroid or saline injections reported bigger improvements in how well they could get around and perform usual activities compared to those in the etanercept-injection group.
The lack of any significant benefit with etanercept, compared to normal saline, was “disappointing,” according to Cohen. “These drugs are expensive, and even though they may be safer than steroids, they’re not devoid of risk,” he said.