Retrospective Evaluation of Clinical Characteristics, Pharmacotherapy and Healthcare Resource Use among Patients Prescribed Pregabalin or Duloxetine for Diabetic Peripheral Neuropathy in Usual Care

Abstract

To evaluate treatment patterns and costs among patients with painful diabetic peripheral neuropathy (pDPN) newly prescribed pregabalin or duloxetine in usual care settings. Using the PharMetrics® Database, patients with pDPN (ICD-9-CM codes 357.2 or 250.6x) newly prescribed pregabalin or duloxetine were identified. Patients initiated on duloxetine (n=713; mean age 55.4 ± 9.5 years) were propensity score-matched with patients initiated on pregabalin (n=713; mean age 56.3 ± 9.3 years). Prevalence of comorbidities, pain-related pharmacotherapy and healthcare resource use/costs (pharmacy, outpatient, inpatient, total) were examined during the 12 months preceding (pre-index) and following (follow-up) the date of the first pregabalin or duloxetine prescription. Both cohorts had multiple comorbidities and a substantial pain medication burden. Among pregabalin patients, use of other anticonvulsants (35.6% vs. 24.7%) and tricyclic antidepressants significantly decreased (18.2% vs. 13.7%) and serotonin-norepinephrine reuptake inhibitors (SNRIs) increased (7.9 % vs. 12.9%) in the follow-up period; all P values <0.05. Among duloxetine patients, use of other SNRIs (8.7% vs. 5.2%) and selective serotonin reuptake inhibitors decreased significantly (32.1% vs. 18.9%) in the follow-up period, but there were increases for anticonvulsants (42.1% vs. 48.4%), benzodiazepines (25.5% vs. 32%), and sedative/hypnotics (22.6% vs. 25.8%); all P values <0.05. Among pregabalin and duloxetine patients there were increases (P<0.05) in pharmacy, outpatient, and total healthcare costs from the pre-index to the follow-up period. Total medication costs in the follow-up period were significantly higher for duloxetine (median $6,763 [IQR $3,970-$10,914]) relative to pregabalin (median $6,059 [IQR $3,277-$9,865]); P=0.0017. Patients with pDPN prescribed pregabalin and duloxetine were characterized by a substantial comorbidity and pain medication burden. Although there were no differences in total healthcare costs, medication costs were significantly higher in the duloxetine cohort relative to the pregabalin cohort.