Impact of comorbidities on pharmacotherapy of painful diabetic neuropathy in clinical practice

Aims: We evaluated the impact of baseline comorbidities on the effectiveness of duloxetine and anticonvulsants (pregabalin/gabapentin) in patients with painful diabetic neuropathy in clinical care. Methods: Outcomes from a 6-month, observational study with 2575 patients initiating/switching DPNP treatment were analyzed post-hoc. Propensity scoring was used to adjust for baseline factors influencing treatment choice in 1523 patients receiving duloxetine or anticonvulsants. Analysis of covariance models with fixed effects for baseline pain, treatment, propensity score, baseline characteristics or comorbidities, and their interaction with treatment were used to estimate LSmean effects on Brief Pain Inventory (BPI) average pain and interference scores. Results: 89.5% of patients reported comorbidities, including hypertension (70.5%), hyperlipidemia (39.2%), and depression (24.8%). Macrovascular complications (37.0%) and 'other chronic pain' (41.5%), particularly joint pain had an impact on both pain treatments, i.e. less improvement of average pain and interference of pain. Better treatment responses with duloxetine vs. anticonvulsants were observed in patients with depression, those with high baseline BPI total interference score, especially general activity, and in patients with joint pain. Conclusions: Comorbidities such as macroangiopathy and depression as well as pain characteristics should be considered in the treatment of DPNP as they may predict the effectiveness of duloxetine and anticonvulsants. (c) 2014 Elsevier Inc. All rights reserved.