Dextromethorphan and quinidine in adult patients with uncontrolled painful diabetic peripheral neuropathy: a 29-day, multicenter, open-label, dose-escalation study.

Background: Pain associated with diabetic peripheral neuropathy (DPN) has a substantial negative impact on patients' quality of life.

Objectives: The primary objective of this study was to evaluate the tolerability of capsules containing dextromethorphan (DM) and quinidine (Q) in patients with painful DPN. A secondary objective was to perform a preliminary assessment of the efficacy of DM/Q in this patient population.