Medication Summary
The goal of pharmacotherapy is to reduce morbidity and prevent complications.
Anticonvulsants
Class Summary
Anticonvulsants are used to manage severe muscle spasms and provide pain relief in neuralgia.
Gabapentin (Neurontin, Gralise)
Gabapentin has anticonvulsant properties and antineuralgic effects; however, the exact mechanism of action is unknown. Gabapentin is structurally related to GABA but does not interact with GABA receptors.
Titration to effect can take place over several days (300 mg on day 1, 300 mg bid on day 2, and 300 mg tid on day 3).
Pregabalin (Lyrica)
Pregabalin is a structural derivative of GABA. The mechanism of action is unknown. It binds with high affinity to the alpha2-delta site (a calcium channel subunit). In vitro, it reduces calcium-dependent release of several neurotransmitters, possibly by modulating calcium channel function. It is FDA approved for neuropathic pain associated with diabetic peripheral neuropathy or postherpetic neuralgia and as adjunctive therapy in partial-onset seizures.
Tricyclic antidepressants
Class Summary
These agents have central and peripheral anticholinergic effects, as well as sedative effects, and block the active reuptake of norepinephrine and serotonin.
Amitriptyline
Amitriptyline is indicated as an analgesic for certain types of chronic and neuropathic pain.
Nortriptyline (Pamelor)
Nortriptyline has demonstrated effectiveness in the treatment of chronic pain. By inhibiting the reuptake of serotonin and/or norepinephrine by the presynaptic neuronal membrane, it increases synaptic concentration of these neurotransmitters in the CNS.
Antidepressant, Selective Serotonin/norepinephrine Reuptake Inhibitor (ssnri)
Class Summary
These agents are a complex group of drugs that inhibit serotonin and norepinephrine reuptake. Some drugs in this class are weak inhibitors of dopamine reuptake with sedative effects.
Duloxetine (Cymbalta)
Duloxetine is indicated for diabetic peripheral neuropathic pain. It is a potent inhibitor of neuronal serotonin and norepinephrine reuptake.
Tables
Feature |
Tumor Infiltration |
Radiation Fibrosis |
Transient Radiation Injury |
Acute Ischemic Injury |
Incidence of pain |
80% |
18% |
40% |
Painless |
Location of pain |
Shoulder, upper arm, elbow, fourth and fifth fingers |
Shoulder, wrist, hand |
Hand, forearm |
Hand, forearm |
Nature of pain |
Dull ache in shoulder, lancinating pains in elbow and ulnar aspect of hand; occasional paresthesias and dysesthesias |
Ache in shoulder; prominent paresthesias in C-5/C-6 distribution of hand and arm |
Ache in shoulder; prominent paresthesias in C-5/C-6 distribution of hand and arm |
Paresthesias in C-5/C-6 distribution of hand and arm |
Severity |
Moderate to severe (severe in 98%) |
Usually mild to moderate (severe in 20-35%) |
Mild |
Mild |
Course |
Progressive neurologic dysfunction; atrophy and weakness in C-7/T-1 distribution, persistent pain; occasional Horner syndrome |
Progressive weakness; panplexus or upper plexus distribution; Horner syndrome uncommon |
Translate weakness with complete resolution |
Acute nonprogressive weakness and sensory loss |
Study findings |
|
|
|
|
Magnetic resonance imaging |
High signal intensity on T2-weighted images; may enhance with gadolinium |
Low signal intensity on T2-weighted images; generally nonenhancing with gadolinium |
No data |
Normal |
Computed tomography |
Mass; circumscribed or diffuse tissue infiltration |
Diffuse tissue infiltration |
Normal |
Angiography demonstrates subclavian artery segmental obstruction |
Electromyography |
Segmental slowing |
Diffuse myokymia |
Segmental slowing |
Segmental slowing |
