SAN DIEGO – Neuropathic pain can be acute instead of chronic, and treatments for the two differ, Scott M. Fishman, M.D., said at a psychopharmacology congress sponsored by the Neuroscience Education Institute.
“There seems to be a prevalent belief that neuropathic pain is only a disorder of chronic illness,” said Dr. Fishman, chief of the pain medicine division and professor of anesthesiology and pain medicine at the University of California, Davis.
Few physicians appear to know that the proper treatment for acute neuropathic pain is corticosteroids, not the anticonvulsants, antiarrhythmics, or antidepressants used conventionally for chronic neuropathic pain, he added.
For a patient who comes out of the operating room with a positional neuropathy or patients with acute-onset neuropathy due to trauma or a cut nerve, treat with corticosteroids. “That acute neuropathic pain actually is a neuritis,” and steroids will cure the pain in most cases.
Dexamethasone dosing for acute neuropathic pain ranges from 4–8 mg orally b.i.d. or t.i.d. to 10–20 mg by IV every 6 hours. Methylprednisolone dosing for acute neuropathic pain usually ranges from 16–32 mg orally b.i.d. or t.i.d. to 40–80 mg by IV every 6 hours, he said.
These regimens also have been used to treat metastatic bone pain or cancerous soft tissue infiltration. Cancer patients frequently develop neuropathic pain due to a tumor's compressing or infiltrating nerves or resulting from paraneoplastic syndromes. The neuropathic pain may be a side effect from surgery, chemotherapy, or radiotherapy. Immunocompromise from cancer also can cause neuropathic pain, as can malignancy-related infection, bleeding, or fracture.
“I've seen oncologists becoming much better at treating pain,” Dr. Fishman said, adding that he's less likely today to see patients with cancer whose neuropathic pain was undertreated by oncologists, compared with a few years ago.
Neuropathic Pain Points Test
Think you know about neuropathic pain? Test yourself with this quiz provided by Dr. Fishman.
Neuropathic pain is distinguished from somatic pain by the fact that:
It's never acute.
It always represents a dysfunction within the nervous system.
It always has a component of “burning.”
It's not responsive to opioids.
Pain associated with nonpainful stimuli is termed:
Hyperalgesia.
Causalgia.
Hyperpathia.
Allodynia.
Most conventionally used medications for neuropathic pain are:
Anticonvulsants.
Antidepressants.
Benzodiazepines.
Antiarrhythmics.
All of the above.
First-line treatment for acute-onset neuropathic pain (within the first week of onset) is usually:
Lidocaine.
Neurontin.
Ibuprofen.
Corticosteroids.
Amitriptyline.
Answers: 1. b; 2. d; 3. e; 4. d.