Effectiveness and Side Effects of Gabapentin
and Pregabalin for Sciatica Pain
Sciatica pain originates from the compression, irritation, or damage of the sciatic nerve, resulting in aching in the lower back that extends through the leg. This condition is often accompanied by limitations in physical functionality and sensory symptoms like numbness or a prickling feeling.
Sciatica is prevalent in 2-5% of the general population and can reach up to 43% in working population cohorts. Factors like poor health, physical stress, obesity, smoking, and occupational workload contribute to its likelihood.
The overall outlook for sciatica is positive, with a favorable clinical progression. Conservative treatment usually leads to the resolution of pain and limitations in daily activities within two weeks. Nonetheless, in approximately 30% of cases, symptoms may endure for one year or beyond.
Typically, pain relief for sciatica relies on the administration of level I and II analgesics (such as paracetamol and mild opioids). In addition, muscle relaxants, corticosteroids, anticonvulsants, and antidepressants are among the other medications commonly used for managing the condition.
The FDA has authorized the use of pregabalin to manage neuropathic pain associated with diabetes mellitus, postherpetic neuralgia, partial-onset seizures, and fibromyalgia. On the other hand, for the management of post-herpetic neuralgia and seizures, gabapentin has received FDA approval.
The off-label prescription of gabapentinoids has significantly increased, raising concerns about potential misuse due to unclear benefits.
When it comes to sciatica, there is limited evidence on the effectiveness of these drugs, with only one trial reporting pain relief for gabapentin compared to a placebo. No studies have specifically investigated the pain relief effects of pregabalin for sciatica.
Impact Of Pregabalin On Leg Pain And Disability
There are no statistically significant differences observed between the effects of pregabalin and placebo when it comes to measuring leg pain, back pain, and disability scores at different time intervals.
Impact Of Pregabalin On Leg Pain And Disability
Statistically significant differences can be found in leg pain between gabapentin and placebo at 2 weeks Significant relief in low back and leg pain with movement at months 3 and 4 has been reported by literature. However, there are no significant differences in disability scores between gabapentin and placebo at 2 weeks.
Gabapentin Vs Pregabalin On Leg Pain And Disability
Gabapentin treatment has shown a reduction in leg pain intensity, while pregabalin also has demonstrated clinically relevant results in reducing pain-associated disability.
However, there are no statistically significant differences between the two medications in terms of leg pain reduction and pain-associated disability after the 8-week treatment period.
Adverse Events Associated With Gabapentinoids
Pregabalin is generally tolerated worse than placebo, with dorsalgia, dizziness, and nausea/vomiting being more common in the pregabalin groups. Serious adverse events are similar between pregabalin and placebo.
Limited data is available for gabapentin, with drowsiness and dizziness being the most mentioned side effects. No serious adverse effects are reported for gabapentin.
Patients with sciatica who are treated with pregabalin should not experience improved pain relief or disability reduction compared to those who received a placebo, even after up to 52 weeks of follow-up.
Likewise, gabapentin demonstrated no significant pain relief or improvement in disability compared to placebo after 8 weeks of treatment.
Although one study reported statistically significant differences in favor of gabapentin at 3-4 months, the observed improvement on the Visual Analog Scale (VAS) assessment was below the clinical relevance threshold of two points out of ten.
Subjects treated with anticonvulsants experienced more adverse effects. The limited number of studies and small sample sizes restrict the generalizability of the results. Short clinical follow-up periods were observed in the studies.
The crossover trial reported positive results for both gabapentinoids, but concurrent use of other therapies may have influenced efficacy and adverse event incidence. Quality of life measurements were not included in the protocol, but one study reported relevant outcomes in this regard.
Among the twelve efficacy outcomes analyzed, levels of evidence were determined for two specific outcomes: leg pain at 8 weeks and disability at 8 weeks, in relation to the treatment with pregabalin.
Safety outcomes, including serious adverse events, dizziness, nausea/vomiting, and somnolence, underwent assessments to determine the levels of evidence.
The evidence for the 8-week leg pain, nausea/vomiting, and somnolence outcomes is downgraded due to bias risk, inconsistency, and imprecision. Higher risks of adverse events and ineffectiveness in treating acute sciatica pain and functional disability with anticonvulsants are indicated.
Limitations include potential publication bias, small sample sizes, and short follow-up periods. Adverse events are not consistently reported, and longer exposure to treatments may reveal additional adverse events.
No evidence supports the use of pregabalin or gabapentin for sciatica pain or low back pain, as their effectiveness is not superior to placebo. Additionally, reported adverse effects raise concerns, making their routine clinical use unsupported.