Predictors Identify Patients Likely to Initiate New Medication for Diabetic Peripheral Neuropathy

LAS VEGAS, NV — At PAINWeek 2012, Wing Chow, PharmD, MPH, of Janssen Scientific Affairs, Raritan, NJ, and colleagues reported that the presence of prior antidepressant or anticonvulsant use is the most significant predictor of a patient receiving new medication for diabetic peripheral neuropathy (DPN).

This study analyzed an employer-based administrative claims database and identified 7,418 patients with newly initiated medication for DPN and 61,013 DPN patients with no newly initiated medication. Newly initiated DPN medications were defined as prescription claims for an opioid, anticonvulsant, antidepressant, or combination of these 3 categories (index medication) within 14 days of the first DPN diagnosis data (index date). Medications were excluded from being considered newly initiated for DPN if the patient had filed any claims for the same drug in the 360 days before the index date or if the patient had a claim in that time period on a non-DPN diagnosis that could be related to other indications for the index medication.

The newly initiated medications were anticonvulsants (48.4%), opioids (27.9%), antidepressants (17.7%), and multiple categories (6%). Cardiovascular comorbidity rates were high for both patients with newly initiated medications (69.7%) and those without (67.8%). Neuropathic pain (other than DPN) and musculoskeletal pain conditions were more commonly diagnosed in the newly initiated group (19% vs. 8.9% and 61.1% vs. 45%, respectively). Mental disorders (newly initiated 9.4% vs. non-initiated 3.7%) and sleep disorders (newly initiated 9.5% vs. non-initiated 6.9%) were more common among patients with newly initiated DPN medications.

Among patients with newly initiated medications for DPN, 53.3% had been exposed to opioid therapy in the pre-index period, 27.5% had received an antidepressant, and 26.9% had received an anticonvulsant. Among patients without newly initiated medications for DPN, 21.6% had received opioid therapy in the pre-index period, 3.4% had received an antidepressant, and 3.3% had received anticonvulsants.

Dr. Chow and colleagues were able to conclude that prior exposure to antidepressants and anticonvulsants was the most significant predictor of receiving a new DPN medication at index, increasing the odds of initiating new DPN drug therapy six-fold. In addition, prior exposure to the WHO pain ladder medication was predictive of a patient receiving a new DPN medication.