The drug, manufactured by Pfizer, has already been approved for use in other chronic pain conditions including fibromyalgia, postherpetic neuralgia, and diabetic neuropathy. With more than 100,000 patients in the US suffering an SCI resulting in neuropathic pain, this announcement offers another strategy for managing a hard to treat condition.
SCI and Neuropathic Pain
Around 40% of those suffering traumatic or non-traumatic spinal cord injury go on to develop neuropathic pain and this often affects patients’ ability to rehabilitate and recover mobility and function. This type of pain is often not confined to the affected area of the spine but may spread to areas above and below the site of injury. In some cases the pain arises just weeks after the initial spinal trauma and for many it can last for decades. A third or so of spinal cord injury patients report neuropathic pain below the injury site which is excruciating or severe. The hope is that these patients will find relief from spinal cord injury neuropathy with pregabalin.
Acute SCI Pain ReliefThe clinical trials forming the basis for the approval were two randomized, double-blind, Phase 3 placebo-controlled trials. Patients received doses of pregabalin for spinal cord injury in the range of 150mg to 600mg, or a placebo. A total of 357 patients were involved in the trials and patients continued taking their existing medications including NSAIDs, opioids, and other pain medications. Most of the patients in these studies had experienced traumatic spinal cord injury, rather than spinal cord compression injuries from chronic spinal stenosis or other cause.
The results of the two trials showed that pregabalin significantly reduced neuropathic pain at twelve and sixteen weeks in the studies compared to placebo. Some patients even had pain relief just a week after starting the treatment, with the nerve pain relief continuing through the trial. Common side-effects of pregabalin reported in the trials were dizziness, dry mouth, fatigue, sleepiness, and peripheral oedema. Like other anti-epileptic drugs, pregabalin also increases the risk of suicidal thoughts and there have been some reports of angioedema and hypersensitivity with the use of this drug.
Lyrica and Weight Gain
Lyrica has also been found to cause problems as regards undesirable weight gain in some patients with issues then arising in terms of physical fitness and ability to engage in rehabilitative exercise regimes, especially if patients are also feeling fatigue and sleepiness in connection to the drug. Extra weight could also lead to further stress and strain on the spine and resulting increases in pain, followed by an increase in the dose of painkillers and the start of a vicious cycle of pain medication, weight gain, and more pain.
First Neuropathic Pain Drug Approved for SCI
Although this recent approval of pregabalin for neuropathic pain in spinal cord injury will likely be welcomed by those unable to find relief through other conservative methods the fact remains that, for many patients, pain is intractable after such back trauma. No other treatment options for this symptom of spinal cord injury have received FDA approval thus far, so pregabalin’s approval is a major step for SCI patients. Most spinal cord injury cases are a result of direct trauma to the spine but there are some suffering as a result of longstanding spinal stenosis with acute spinal slippage or disc herniation leading to severe spinal cord bruising and damage. Clearly, prevention of spinal cord injury through early and appropriate treatment of spinal stenosis is preferable although not always possible. At least, now, patients are able to receive pregabalin for spinal cord injury neuropathic pain, provided that the side-effects are tolerated.