Long-term safety and tolerability of oxcarbazepine in painful diabetic neuropathy.

Background: Painful diabetic neuropathy is a common complication of diabetes and often resistant to treatment with standard analgesics. Treatment of diabetic neuropathy with antiepileptic drugs may provide pain relief.

Aim: To evaluate the long-term safety and tolerability of oxcarbazepine in two studies investigating the treatment of diabetic neuropathy.

Objectives: Patients with diabetes and a history of neuropathic pain were included. Study 1 was a multicenter, open-label study comprising a screening and 12-month treatment phase. Study 2 was a multicenter, open-label extension to a double-blind, randomized study. Oxcarbazepine was initiated at 300 mg/day and titrated over 4 weeks to tolerability or a maximum dose of 900 mg b.i.d. Safety was assessed by monitoring adverse events (AEs), serious AEs (SAEs), hematology, blood chemistry, urinalysis values, and vital signs.

Results: Adverse events were most frequently reported in the nervous and gastrointestinal systems; 20.5% and 21.6% of patients withdrew because of AEs in study 1 and study 2, respectively. SAEs were reported in 13.7% and 14.4% of patients in study 1 and study 2, respectively.

Conclusions: Long-term treatment with oxcarbazepine is generally well tolerated in patients with painful diabetic neuropathy. Rapid titration of oxcarbazepine may be responsible for discontinuations resulting from AEs during early stages of treatment.