Techniques of opioid administration

Opioids continue to be the main pharmacological treatment for severe acute pain. Traditional methods of opioid administration (oral, intramuscular, subcutaneous) are more effective in managing pain if the treatment regimens are individualized and dosages are titrated to effect (pain relief). Oxycodone, an opioid agonist similar in potency to morphine, has proved useful as an oral step-down analgesic in the treatment of acute postoperative pain for a number of surgical procedures (orthopaedic, abdominal, gynaecological). It is also a valuable alternative opioid to morphine intravenous patient-controlled analgesia (IV PCA) in those patients who experience severe unpleasant side effects, such as nausea and hallucinations. Other PCA modalities available for opioid administration in the treatment of acute pain include epidural and transmucosal (intranasal, sublingual, buccal). Transdermal delivery of highly lipid-soluble opioids is available for the treatment of severe pain in chronic and palliative care. This passive drug delivery system is not suitable for the routine management of severe acute pain because rapid and reliable changes to the delivery rate are not possible. However, advances in transdermal delivery system technology have led to the development of a non-invasive PCA system for the management of acute postoperative pain, which utilizes the process of iontophoresis. This has the potential to be a valuable modality in the future management of acute postoperative pain.