A few weeks ago I was approached by my friend, and the florist at the hospital in which I work, about pain she was experiencing in her left lower leg.
The pain was of such a severity that she was finding it hard to work. She had been to see a physiotherapist who had asked her to speak to her doctor about it, and I was that lucky person.
Upon my review I suspected her pain was likely arising from the spine, especially given her description of a burning type character to the pain and the associated paresthesia, numbness, and weakness of her toe extension.
A CT scan confirmed that she had a disc prolapse at the L4/5 level towards the left side, impinging both the exiting L4 nerve root within the foramina and the descending L5 nerve root in the lateral recess, which correlated well with her clinical presentation.
As such the diagnosis of sciatica proved to be quite straightforward.
With that achieved, I proceeded onto outlining for her a treatment plan, which aimed to educate her about the condition, manage her symptoms, and return her at least to her previous level of function but ideally beyond that to reduce the likelihood of recurrent pain.
She was therefore asked to return to see her physiotherapist and I discussed with her an approach to analgesia, which included the advice to trial Pregabalin.
Pregabalin, otherwise known as Lyrica, has been available for use in Australia for a few years now for the treatment of Neuropathic pain.
It has proven to be effective in reducing the pain of diabetic peripheral neuropathy, postherpetic neuralgia, as well as reducing the experience of allodynia and hyperalgesia. It works by reducing neurotransmitter (chemicals in the brain) release in a manner thought relevant to this type of pain. As such, we have taken to using it in a number of other conditions thought to result in neuropathic pain, with sciatica being a common indication in the patient cohort I see.
So you can imagine my pleasure when I came across the recent publication of a randomised controlled trial within the New England Journal of Medicine titled “Trial of Pregabalin for Acute and Chronic Sciatica”.
I know some of the authors of the paper as it originates from The George Institute for Global Health and the Sydney Medical School. And so to stop the beating of my heart, my eyes darted to the conclusion, after which my head flung back and a loud and gutteral ‘Noooooooo!!’ emanated from the depths of my soul.
Of course whilst I jest and indulge myself with literary joy, I must admit I was indeed saddened by the outcome, which stated that no benefit was found from the use of Pregabalin in the context of sciatica.
You see, as a doctor, I feel great pleasure in feeling that I am actually doing something for my patient, and as a physician that something is often the writing of a prescription.
Whilst I appreciate that there is great value in educating patients about their condition and whilst with maturity, I am learning to appreciate that in some circumstances inaction is the greatest action, it doesn’t take away from the desire to meet the patient’s expectations and central to that is the need to be doing something.
In the context of sciatica that something is in the prescribing of a ‘pain killer’ because they came to you to ‘kill their pain’.
With that aim then, lets look a little further into the effectiveness of Pregabalin in ‘killing the pain’.
The authors enrolled 209 patients suffering with moderate to severe sciatica for at least the past week and up to a year.
The group of patients was then randomised to receive either Pregabalin (up to a maximum dose of 300mg twice daily) or placebo for a period of 8 weeks in addition to usual care, with usual care being interventions that were considered suitable by the trial clinician (including physical therapies and other analgesic medications).
The primary outcome measured was the average leg pain intensity, and this was measured at 8 weeks and then again at 52 weeks.
Other secondary outcomes being collected were measures of disability, global perceived effect, quality of life, workplace absenteeism, and health care utilization.
Whilst there was an improvement in pain scores in both groups at all time points assessed, there was no statistical significant difference between those that received Pregabalin versus those receiving placebo in any of the outcome measures studied.
It should be noted, albeit not surprisingly, that there was a significantly greater number of adverse events reported in the Pregabalin group, with dizziness being the most commonly reported complication.
So what about my patient? Well she has improved.
Whether it was simply the 3 weeks that had passed or the result of either the physical therapy or the peri-neural injection of steroid she had received is difficult to determine, but what it seems to me now is that the prescribing of Pregabalin was of no greater benefit than simply the act of me prescribing something!
Whether that justifies the cost of Pregabalin I might leave to you to contemplate and something for us to discuss in future perhaps.
What I do know is that I received a lovely bunch of flowers from my friend.
Reference: Mathieson S, Maher C, et al. Trial of Pregabalin for Acute and Chronic Sciatica. NEJM 2017; 376: 1111-1120
