A randomized, controlled trial of oxycodone versus placebo in patients with
postherpetic neuralgia and painful diabetic neuropathy treated with pregabalin.
Author(s): Zin CS, Nissen LM, O'Callaghan JP, Duffull SB, Smith MT, Moore BJ.
Affiliation(s): The University of Queensland, School of Pharmacy, St Lucia Campus, QLD 4072,
Publication date & source: 2010, J Pain. , 11(5):462-71
The aim of this randomized double-blind, placebo-controlled, parallel-group study
was to evaluate the efficacy, safety, and tolerability of pregabalin in
combination with oxycodone or placebo, in patients with either postherpetic
neuralgia (PHN) or painful diabetic neuropathy (PDN). After a 7-day washout
period, 62 patients were randomized to receive either oxycodone mixture 10 mg/day
or placebo mixture for 1 week. Patients were then started on open-label
pregabalin (75, 150, 300 and 600 mg/day) according to a forced titration dosing
regimen, while continuing the same dosage of oxycodone or placebo for 4 weeks.
The primary efficacy measure was a decrease in the pain-intensity score of at
least 2cm and a pain score <4cm measured using a 10-cm visual analogue scale
(VAS) following pregabalin dosage escalation and treatment for 4 weeks. Secondary
efficacy measures included sleep interference and the Neuropathic Pain Scale.
There were similar levels of overall efficacy between pregabalin/oxycodone and
pregabalin/placebo groups in relieving PHN and PDN related pain. PERSPECTIVE:
Peripheral neuropathic pain presents commonly in clinical practice, and 2 of its
most prevalent types are PHN and PDN. Currently available treatments provide some
degree of pain relief in approximately 40-60% of patients, leaving the remainder
with unremitting pain. Although this study supports the effectiveness of
pregabalin in the treatment of PHN or PDN, it also shows that the addition of a
low dose of oxycodone at 10mg/day does not enhance the pain-relieving effects of