Efficacy of botulinum toxin type a for treating chronic low back pain

Botulinum toxin type A for treating chronic low back pain: A double blinded randomized control study

BACKGROUND

Low back pain (LBP) is a prevalent issue that orthopedic surgeons frequently address in the outpatient setting. LBP can arise from various causes, with stiffness in the paraspinal muscles being a notable contributor. The administration of Botulinum toxin type A (BoNT-A) has been found to alleviate back pain by relaxing these stiff muscles. While BoNT-A is approved for use in numerous conditions, a limited number of randomized clinical trials (RCTs) validate its efficacy specifically for treating LBP.

AIM

To study the safety and the efficacy of BoNT-A in minimizing pain and improving functional outcomes in patients of chronic LBP (CLBP).

METHODS

In this RCT, adults aged 18-60 years with mechanical LBP persisting for at least six months were enrolled. Participants were allocated to either the Drug group, receiving 200 Ipsen Units (2 mL) of BoNT-A, or the Control group, which received a 2 mL placebo. Over a 2-month follow-up period, both groups were assessed using the Visual Analog Scale (VAS) for pain intensity and the Oswestry Disability Index (ODI) for disability at the start and conclusion of the study. A decrease in pain by 50% was deemed clinically significant.

RESULTS

The study followed 40 patients for two months, with 20 in each group. A clinically significant reduction in pain was observed in 36 participants. There was a statistically significant decrease in both VAS and ODI scores in the groups at the end of two months. Nonetheless, when comparing the mean score changes, only the reduction in ODI scores (15 in the placebo group vs 16.5 in the drug group, clinically insignificant) was statistically significant (P = 0.012), whereas the change in mean VAS scores was not significant (P = 0.45).

CONCLUSION

The study concludes that BoNT-A does not offer a short-term advantage over placebo in reducing pain or improving LBP scores in CLBP patients.

Injection Botulinum Toxin A in Treatment of Resistant Chronic Low Back Pain: A Prospective Open-Label Study

Objective

The aim of this study was to evaluate the effect of botulinum toxin A (BTX-A) injection on patients with chronic low back pain (CLBP).

Design

In this open-label prospective study, patients with CLBP who satisfied inclusion and exclusion criteria received 100 units of BTX-A injection. Patients were followed up at four weeks, three months, and six months after injection. Pain and function were assessed with visual analog scale (VAS), Roland-Morris Disability Scale (RMS), and Oswestry Disability Index (ODI) at baseline and subsequent visits.

Results

A total of 19 participants with a mean age of 41.11 years completed the study. Compared to baseline, a significant improvement in all scores was observed that persisted up to six months post-injection (P<0.001). Only two patients reported transient injection site pain that improved over two to three days without any treatment.

Conclusion

BTX-A injection is safe and improves pain and function in patients with resistant CLBP. The effects are more beneficial when the population is more homogenous in diagnosis and devoid of negative predictors for the outcome.

Efficacy, acceptability, and safety of muscle relaxants for adults with non-specific low back pain: systematic review and meta-analysis

OBJECTIVE

To investigate the efficacy, acceptability, and safety of muscle relaxants for low back pain.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, CINAHL, CENTRAL, ClinicalTrials.gov, clinicialtrialsregister.eu, and WHO ICTRP from inception to 23 February 2021.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Randomised controlled trials of muscle relaxants compared with placebo, usual care, waiting list, or no treatment in adults (≥18 years) reporting non-specific low back pain.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently identified studies, extracted data, and assessed the risk of bias and certainty of the evidence using the Cochrane risk-of-bias tool and Grading of Recommendations, Assessment, Development and Evaluations, respectively. Random effects meta-analytical models through restricted maximum likelihood estimation were used to estimate pooled effects and corresponding 95% confidence intervals. Outcomes included pain intensity (measured on a 0-100 point scale), disability (0-100 point scale), acceptability (discontinuation of the drug for any reason during treatment), and safety (adverse events, serious adverse events, and number of participants who withdrew from the trial because of an adverse event).

RESULTS

49 trials were included in the review, of which 31, sampling 6505 participants, were quantitatively analysed. For acute low back pain, very low certainty evidence showed that at two weeks or less non-benzodiazepine antispasmodics were associated with a reduction in pain intensity compared with control (mean difference -7.7, 95% confidence interval-12.1 to-3.3) but not a reduction in disability (-3.3, -7.3 to 0.7). Low and very low certainty evidence showed that non-benzodiazepine antispasmodics might increase the risk of an adverse event (relative risk 1.6, 1.2 to 2.0) and might have little to no effect on acceptability (0.8, 0.6 to 1.1) compared with control for acute low back pain, respectively. The number of trials investigating other muscle relaxants and different durations of low back pain were small and the certainty of evidence was reduced because most trials were at high risk of bias.

CONCLUSIONS

Considerable uncertainty exists about the clinical efficacy and safety of muscle relaxants. Very low and low certainty evidence shows that non-benzodiazepine antispasmodics might provide small but not clinically important reductions in pain intensity at or before two weeks and might increase the risk of an adverse event in acute low back pain, respectively. Large, high quality, placebo controlled trials are urgently needed to resolve uncertainty.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019126820 and Open Science Framework https://osf.io/mu2f5/.

Are paraspinous intramuscular injections of botulinum toxin a (BoNT-A) efficient in the treatment of chronic low-back pain? A randomised, double-blinded crossover trial

BACKGROUND

Treatment for patients with chronic low-back pain (LBP) is a public health issue. Intramuscular injections of botulinum toxin A (BoNT-A) have shown an analgesic effect on LBP in two previous randomized controlled studies. The objective of the study was to verify the efficacy of paravertebral injections of BoNT-A in patients with LBP.

METHODS

Patients were included in this phase 3 randomized double-blinded trial comparing the efficacy of BoNT-A versus placebo in a crossover study on LBP. Both groups received 200 units of BoNT-A in paravertebral muscles or a placebo, and vice versa at Day 120. The main judgment criterion was LBP intensity 1 month after the injections, evaluated by using a visual pain scale (VAS). Secondary assessment criteria included: LBP intensity 90 and 120 days after injection day; number of days when an allowed antalgic oral treatment was needed in between each evaluation; functional disability measured by the Quebec Back Pain Disability Scale; quality of life; inability to work; patient satisfaction in relation to the treatment's effect; spinal mobility; and strength of spinal muscles, measured by isokinetic technique.

RESULTS

Nineteen patients completed the study. There was no significant difference between the groups' average LBP during the last 8 days at Day30 (p = 0.97). There was no significant difference between the two groups regarding the secondary assessment criteria (p > 0.05).

CONCLUSIONS

Injections of BoNT-A in the paravertebral muscles were not found to be effective to relieve chronic LBP. The limits of the study are that the dose of BoNT-A used was lower than in other studies, and that the limited number of patients included may explain the negative results.

TRIAL REGISTRATIONS

Identifiers: NCT03181802 . Unique Protocol ID: CHUBX2003.

Abobotulinum Toxin A in the Treatment of Chronic Low Back Pain

Chronic low back pain is a debilitating condition with a complex and multifactorial pathophysiology. Botulinum neurotoxins (BoNTs) have strong analgesic effects, as shown in both animal models of pain and in human beings. A randomized, double-blind, placebo-controlled, parallel format study to investigate the efficacy of abobotulinum toxin A (aboA) in chronic low back pain was conducted. The study cohort consisted of 18 patients who received 100 units of aboA into each of the five lumbar extensor spinae muscles unilaterally or bilaterally (total dose 500 to 1000 units), and 19 who received normal saline of the same volume. The level of pain and quality of life were assessed using the visual analogue scale (VAS) and three questionnaires including the Oswestry Low Back Pain Disability Questionnaire (OLBPDQ). Patients’ perception of improvement was recorded via patient global impression of change (PGIC). The primary outcome measure, the proportion of responders with VAS of <4 at 6 weeks, was not met, but the data was significantly in favor of aboA at 4 weeks (p = 0.008). The total Oswestry score representing quality of life improved in the aboA group compared to the placebo group (p = 0.0448). Moreover, significantly more patients reported their low back pain as “much improved” in the abobotulinum toxin A group (0.0293).