The Rising Role of Anticonvulsants in Treating Pain in California Workers’ Compensation


 

Navigating the complexities of chronic pain and opioid addiction is an ever-present challenge for those in the workers’ compensation industry. A few anticonvulsant drugs are commonly seen in treatment plans for some pain conditions.  A recent study by the California Workers Compensation Research Institute reported the 2nd most common non-exempt drug undergoing UR in first four months of 2018 was gabapentin at 12.6% (up almost 10 percent from 11.5% in the same period of 2017). Pregabalin, sold under the brand name Lyrica, was reported to account for 4.3% of non-exempt drugs undergoing UR (up from 3.5% in 2017, a 23% jump).  As the regulatory landscape adapts to address each issue, California’s Medical Treatment Utilization Schedule (MTUS) and ACOEM-MD Guidelines provide direction on the responsible use of pregabalin (Lyrica) and gabapentin (Neurontin).

Gabapentin and pregabalin are both listed as “non-exempt” on the CA MTUS Drug List and as such require authorization through prospective review before prescribing or dispensing.

Gabapentin was approved in 1993 by FDA for treatment of postherpetic neuralgia as well as partial seizures.  Research has shown it prevents pain related responses to various forms of neuropathic pain, whether caused by infection, diabetes or nerve or spinal cord injury.

Pregabalin/Lyrica was approved in 2004 by the FDA also for postherpetic neuralgia and partial seizures but also for fibromyalgia and neuropathic pain associated with diabetic peripheral neuropathy.

 

Overtime they have been more commonly tried “off-label” in other forms of pain.

Per California MTUS and ACOEM MD Guidelines, Gabapentin and Pregabalin are recommended for the following:

  • Complex Regional Pain Syndrome (CRPS)-Moderate to Severe:  Previously referred to as Reflex Sympathetic Dystrophy (RSD) or Causalgia, SHORT TERM USE ONLY.
  • Fibromyalgia and Tender Points-Chronic and severe; Concurrent functional restoration program is recommended.  Consider a trial if there is an inadequate response to NSAIDs, tricyclic antidepressants, exercise or other interventions.   Duration of use may be indefinite.
  • Neuropathic Pain Chronic:  Neuropathic, Diabetic Peripheral Neuropathy, Peripheral Neuropathy, Postherpetic neuralgia, Occupational toxic neuropathies- Moderate to Severe. Trial for painful peripheral neuropathies that have not responded to other treatments. Duration of use may be indefinite.
  • Chronic pain-persistent with neuropathic features that has not responded to other treatments, e.g., NSAIDs, therapeutic exercises, or tricyclic anti-depressants.
  • Peri-operative management of Low Back Pain (Acute, Perioperative): Duration is generally limited to 2 to 6 weeks following surgical procedure.  Recommended to reduce opioid use when used for perioperative pain management, especially for patients with adverse effects from opioids. 
  • Chronic Brachial Plexus Injuries (Shoulder): Trial for painful peripheral neuropathies that have not responded to other treatments; duration of use may be indefinite.

 

 In addition, Gabapentin is recommended also for the following:

  • Peri-operative management of Cervical and Thoracic Spine Disorders.  Duration is generally limited to 2 to 6 weeks following surgical procedure.  Recommended to reduce opioid use when used for perioperative pain management, especially for patients with adverse effects from opioids. 
  • Peri-operative management of Hip and Groin Disorders and Knee Disorders.  Duration of use is a few days to approximately a week post procedure.  Strongly recommended to reduce the need for post-operative opioid pain relief. Particularly for patients with adverse effects from opioids.
  • Spinal Stenosis:  Recommended when severe neurogenic claudication from spinal stenosis limits walking distance.

 

Per California MTUS and ACOEM MD Guidelines, Gabapentin is NOT recommended for the following: 

  • Chronic non-neuropathic pain or cervicothoracic pain
  • Acute hip and groin pain
  • Acute knee pain
  • Acute shoulder pain

 

California’s MTUS Guidelines offer no recommendation on Gabapentin and Pregabalin (neither against or for) on the following:

  • Cervical and Thoracic Spine Disorders-Radicular Pain Syndromes
  • Acute and Chronic Low Back Pain
  • Chronic Shoulder Pain
  • Non-neuropathic shoulder trigger points and myofascial pain

 

 Side Effects

Drowsiness, weakness, dizziness, confusion, headache, seizures, blurred vision, anxiety, strange or unusual thoughts, nausea, vomiting, heartburn, dry mouth, heartburn, rash, constipation, weight gain, and itching among others.  

A growing concern in the medical community is the potential for increased opioid deaths related to Gabapentin’s use in concert with opioids.

 

 

 - Doug Benner, MD
   EK Health Chief Medical Officer