Effectiveness of pregabalin for treatment of chronic cervical radiculopathy with upper limb radiating pain: an 8-week, multicenter prospective observational study in Japanese primary care settings

2. Cervical radicular pain

INTRODUCTION

Cervical radicular pain is pain perceived in the upper limb, caused by irritation or compression of a cervical spine nerve, the roots of the nerve, or both.

METHODS

The literature on the diagnosis and treatment of cervical radicular pain was retrieved and summarized.

RESULTS

The diagnosis is made by combining elements from the patient's history, physical examination, and supplementary tests. The Spurling and shoulder abduction tests are the two most common examinations used to identify cervical radicular pain. MRI without contrast, CT scanning, and in some cases plain radiography can all be appropriate imaging techniques for nontraumatic cervical radiculopathy. MRI is recommended prior to interventional treatments. Exercise with or without other treatments can be beneficial. There is scant evidence for the use of paracetamol, nonsteroidal anti-inflammatory drugs, and neuropathic pain medications such as gabapentin, pregabalin, tricyclic antidepressants, and anticonvulsants for the treatment of radicular pain. Acute and subacute cervical radicular pain may respond well to epidural corticosteroid administration, preferentially using an interlaminar approach. By contrast, for chronic cervical radicular pain, the efficacy of epidural corticosteroid administration is limited. In these patients, pulsed radiofrequency treatment adjacent to the dorsal root ganglion may be considered.

CONCLUSIONS

There is currently no gold standard for the diagnosis of cervical radicular pain. There is scant evidence for the use of medication. Epidural corticosteroid injection and pulsed radiofrequency adjacent to the dorsal root ganglion may be considered. [Correction added on 12 June 2023, after first online publication: The preceding sentence was corrected.].

Dispensing patterns of drugs used for neuropathic pain and adherence to NeuPSIG guideline: an observational study

Background

Neuropathic pain is a common chronic ailment that can be challenging to treat because of the heterogeneity of its etiologies, symptoms, and underlying mechanisms. Drugs to treat neuropathic pain are highly prescribed; however, limited data exist on the rates and patterns of dispensing in Lebanon. This study was conducted to assess the patterns of dispensing neuropathic pain drugs and adherence to NeuPSIG guideline in the Lebanese adult population. An observational study was conducted at 30 community pharmacies over 10 months. Adults presenting to the community pharmacy with a prescription of at least one pain medication and diagnosed with a neuropathic pain disorder were interviewed using a questionnaire that included demographic characteristics of patients, comorbidities, neuropathic pain disorder type, physicians’ specialty, and the class and number of prescribed medications.

Results

A total of 360 patients diagnosed with painful neuropathy were enrolled in our study. The mean patients’ age was 50.2 years. Guideline-recommended first-line agents (serotonin–norepinephrine reuptake inhibitors, tricyclic antidepressants, and gabapentinoids) were prescribed to 278 patients (77.2%), with pregabalin being the most used drug (60.5%), nonsteroidal anti‐inflammatory drugs (46.8%), opioids (15.8%), and topical agents (5.5%). Combination treatment for neuropathic pain was prescribed to 78.3% of patients.

Conclusions

In Lebanon, neuropathic pain management comply with the international NeuPSIG guideline. Pregabalin is the most commonly used drug, and combination treatments are usually needed to alleviate neuropathic pain.

Direct and Indirect Pathways for Health-Related Quality of Life Change from Pain Improvement in Neuropathic Pain Patients with Spine Diseases: Path Analysis with Structural Equation Modeling Using Non-Interventional Study Results of Pregabalin

Background

Chronic low back pain or chronic cervical pain often has a neuropathic pain (NeP) component and patients with these conditions complain of sleep deprivation, loss of physical function, and reduced productivity due to pain. The objective of this study was to clarify the pathway by which pain, sleep disturbance due to pain, and physical function status influence QOL measures in chronic low back pain patients with NeP associated with lumbar spine diseases (CLBP-NeP) and in chronic cervical pain patients with NeP associated with cervical spine diseases (CCP-NeP).

Methods

A model assuming pain numeric rating scale (NRS), pain-related sleep interference scale (PRSIS), and functional indices (Roland Morris Disability Questionnaire [RMDQ], Neck Disability index [NDI]) as factors that can affect outcomes such as QOL (calculated using EuroQoL 5 Dimensions (EQ-5D)), the Patient Global Impression of Change (PGIC), and the Clinical Global Impression of Change (CGIC) was developed using structural equation modeling.

Results

Overall trends were frequently observed in both patients with CLBP-NeP and CCP-NeP. Pain NRS had the largest comprehensive direct impact on QOL based on EQ-5D and an overall impression of changing symptoms. The effects of pain NRS on each outcome were largely due to direct pain-related effects; however, for EQ-5D, an indirect effect via functional improvement was the primary factor.

Conclusion

Although the results of this study suggest that the indirect functional improvement of pain relief may not be recognized as a significant component of therapeutic effects by both physicians and patients, the pain-relieving intervention contributes directly to improvement of patients' overall QOL and also indirectly via functional improvement in Japanese primary care settings. Accordingly, to achieve the therapeutic goal for patients with NeP and minimize the impact of pain burden, our findings indicate that pain relief interventions are also crucial from the perspective of the patient's HRQOL.

Effectiveness of Pregabalin Treatment for Neuropathic Pain in Patients with Spine Diseases: A Pooled Analysis of Two Multicenter Observational Studies in Japan

Purpose

Neuropathic pain (NeP) is common among patients with chronic pain associated with spine diseases. Practical effectiveness of pregabalin, one of the first-line treatments for NeP, has not been evaluated in an entire population of patients with spine diseases, including various pathophysiological conditions. This pooled analysis aimed to evaluate the therapeutic value of pregabalin for chronic pain with NeP component in patients with spine diseases in routine primary care settings.

Patients and Methods

We pooled data from two 8-week prospective observational cohort studies for patients with chronic low back pain with accompanying lower limb pain (NeP component), and patients with chronic cervical pain and accompanying upper limb radiating pain (NeP component) in routine primary care settings in Japan. For both studies, patients were treated for 8 weeks with pregabalin (alone/with other analgesics) or usual care with conventional analgesics (eg, non-steroidal anti-inflammatory drugs). Changes in pain numerical rating scale (NRS), Pain-Related Sleep Interference Scale (PRSIS), and EuroQol 5-dimension 5-level (EQ-5D-5L) scores from baseline to week 8 were summarized and compared between the pregabalin and usual care groups, and also for subgroups of primary diagnosis. Safety was evaluated by adverse events (AEs) in the pregabalin group.

Results

The pooled dataset comprised 700 patients (pregabalin group: 302; usual care group: 398). All patient-reported outcomes (PRO) scores significantly improved from baseline to week 8 in the pregabalin than in the usual care group (NRS: P<0.0001; PRSIS: P<0.0001, and EQ-5D-5L: P=0.0006). Overall, all three PRO measures showed greater improvement in the pregabalin than in the usual care group, irrespective of the primary diagnosis. AEs were reported in 36.1% of the pregabalin group.

Conclusion

This analysis suggested multi-faceted effectiveness of treatment with pregabalin from the patient’s perspectives under a “real-world” practice in all patients with chronic NeP from various spine diseases.

A Cost-Effectiveness Analysis Of Pregabalin For The Treatment Of Patients With Chronic Cervical Pain With A Neuropathic Component In Japan

Purpose

To evaluate the cost-effectiveness of pregabalin versus other analgesics among patients with chronic cervical pain with neuropathic components during routine clinical practice in Japan.

Patients and methods

The analysis considered patients with chronic cervical pain with a neuropathic pain component (radiating pain to the upper limb) and who were treated with pregabalin with or without other analgesics (pregabalin-containing treatments) or other analgesics alone (usual care) for 8 weeks. Other analgesics included non-steroidal anti-inflammatory drugs (NSAIDs), weak opioids, antidepressants, and antiepileptic drugs. A Markov cohort simulation model was constructed to estimate costs and effectiveness (in terms of quality-adjusted life-years, QALYs) of each treatment over a 12-month time horizon. In the model, patients transitioned among three states of pain severity (no/mild, moderate, and severe). Data were derived from a previous observational study (pregabalin-containing treatments, n = 138; usual care, n = 211). Cost inputs included medical costs and productivity losses. QALYs were calculated using the EuroQol five-dimensional, five-level questionnaire. The cost-effectiveness was evaluated using incremental cost-effectiveness ratios (ICERs). Sensitivity analyses were conducted to assess the robustness of results.

Results

From the payer's perspective, pregabalin-containing treatments were more costly (JPY 61,779 versus JPY 26,428) but also more effective (0.763 QALYs versus 0.727 QALYs) than the usual care, with an ICER of JPY 970,314 per QALY gained. From the societal perspective, which also included productivity losses, the ICER reduced to JPY 458,307 per QALY gained. One-way sensitivity analyses demonstrated the robustness of the results. Given a hypothetical threshold value of one additional QALY of JPY 5,000,000, the probability of pregabalin-containing treatments being cost-effective was 100%.

Conclusion

Compared with using other analgesics alone, the use of pregabalin, alone or in addition to other analgesics, was cost-effective for the treatment of chronic cervical pain with a neuropathic pain component in Japan.