Use of antiepileptics and tricyclic antidepressants in cancer patients with neuropathic pain.

Using a large US health insurance claims database, we identified all persons aged > or =18 years with > or =2 medical encounters with diagnoses of cancer and > or =2 medical encounters with diagnoses of painful neuropathies in calendar year (CY) 2000; persons with seizure disorders or depression were excluded. We then examined the use of antiepileptics (AEDs), tricyclic antidepressants (TCAs) and other pain-related pharmacotherapy among these selected persons, as proxied by pharmacy dispenses. A total of 956 persons were identified who met all entry criteria; 17% received AEDs in CY2000 and 14% received TCAs. Gabapentin was the most widely used AED (92% of all AED patients); amitriptyline was the most widely used TCA (79% of all TCA patients). Patients who received AEDs and/or TCAs were similar in age, gender and the presence of metastases to those who had not received these medications; they were more likely to have received other pain-related therapies, however, including short-acting opioids (73% vs. 53%; P < 0.01) and long-acting opioids (23% vs. 8%; P < 0.01). Use of AEDs and TCAs appears to be relatively low among cancer patients with painful neuropathies. Further research is needed to better understand reasons for this finding, as well as its potential implications for pain management in this patient population.