Transdermal oxycodone patch for the treatment of postherpetic neuralgia: a randomized, double-blind, controlled trial

To evaluate the efficacy, systemic exposure, safety and tolerability of a transdermal oxycodone patch containing tocopheryl phosphate mixture (TPM) in patients with postherpetic neuralgia (PHN). The study was a Phase IIa, multicenter, randomized, double-blind, vehicle-controlled crossover study. While the TPM/oxycodone patch did not significantly improve 'average' Numeric Pain Rating Scale scores versus vehicle patch, patients reporting high levels of paresthesia (n = 9) showed a trend toward improved pain reduction. The TPM/oxycodone patch resulted in a low systemic exposure to oxycodone and was well tolerated. The TPM/oxycodone patch delivered oxycodone to the site of perceived pain in subjects suffering from PHN, but did not provide analgesia for the broad PHN indication.