Pharmaceutical Therapy for Radiculopathy

Treatment of painful radiculopathies with capsaicin 8% cutaneous patch

BACKGROUND AND OBJECTIVE

The treatment of neuropathic pain due to low-back (lumbosacral) radiculopathies, a common source of neuropathic pain, is challenging and often requires a multimodal therapeutic approach. The capsaicin 8% patch is the first topical analgesic licensed for peripheral neuropathic pain. To evaluate this treatment, a subset of patients with painful radiculopathy (lumbar and cervical, including ventral and dorsal rami) enrolled into the multicenter, non-interventional QUEPP study (Qutenza ² - safety and effectiveness in peripheral neuropathic pain) was analyzed.

METHODS

Of the 1044 study participants, 50 were diagnosed with painful radiculopathy as only peripheral neuropathic pain syndrome and were eligible for evaluation. Patients received a single treatment (visit 1) with follow-up visits 2-5 at weeks 1-2, 4, 8 and 12. Parameters assessed at all visits included pain intensity, neuropathy symptoms and side effects. Quality of life (SF-12) and painDETECT ¹ questionnaires were completed at baseline and final visit. Data was analyzed by patch application site and duration of pain.

RESULTS

Topical treatment led to a significant decrease of pain intensity between weeks 1/2 and week 12 versus baseline at the application sites representing dermatomes of ventral (N = 26) and dorsal rami (N = 13) of spinal nerves. A significant decline (p ≤ .001) of numeric pain rating scale scores was observed between weeks 1/2 following patch application and the end of observation (week 12) in the overall radiculopathy group (N = 50), and the groups with either 3 months to 2 years (N = 14) or >2 years (N = 23) duration of pain. Pain relief of at least 30% was observed in 50.0%, 71.4% and 39.1% of patients in the respective groups. Four patients experienced in total seven adverse drug reactions (application site pain or pruritus).

CONCLUSION

Effective neuropathic pain relief was observed after patch application within the innervation territories of both dorsal and ventral branches of the spinal nerve. Further controlled randomized trials are indicated.

Pharmacologic Therapies in Musculoskeletal Conditions

Musculoskeletal conditions are common, and there are many options for pharmacologic therapy. Unfortunately, there is not strong evidence for the use of many of these medications. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are generally first-line medications for most musculoskeletal pain, but there is more evidence these medications are not as safe as once thought. Other analgesic and antispasmodic medications can be effective for acute pain but generally are not as effective for chronic pain. Antidepressants and anticonvulsants can be more effective for chronic or neuropathic pain. Topical formulations of NSAIDs can be effective for pain with fewer side effects.

Novel Treatment of Radicular Pain With a Multi-Mechanistic Combination Topical Agent: A Case Series and Literature Review

Introduction

Pharmacologic treatment of radicular pain with oral medications is limited by adverse effects and concern for dependence. While topical formulations have been explored in pain research, there is no published literature evaluating the efficacy in radicular pain. We present the first three cases of radicular pain successfully treated with a topical formulation of diclofenac, ibuprofen, baclofen, cyclobenzaprine, bupivacaine, gabapentin, and pentoxifylline (T7).

Case Presentation

Case series evaluating T7 for treatment of radicular pain in a single, outpatient pain center. Pain was rated on the numeric rating scale (NRS) on initial evaluation and follow up after a trial of T7. One to two grams of T7 was applied to the affected area 3 - 4 times daily in addition to the patient’s baseline pharmacologic management. Three patients with median age of 50 (range, 39 to 65) and diagnosis of cervical and/or lumbosacral radicular pain participated. Two of the three had chronic radicular pain despite use of analgesic agents, spinal injections and failed spinal surgery syndrome. Each reported subjective improvement in radicular pain, function and sleep. There was an average decrease in NRS score consistent with 30% - 40% global improvement in symptoms, clinically significant based on the minimal clinically important difference for radicular pain. T7 was well tolerated without adverse reactions. Surgery was prevented or delayed in all cases.

Conclusions

This is the first report of the successful treatment of radicular pain with a topical agent. This highlights the need for randomized, prospective study of both single and compounded topical agents for treatment of radicular pain.