Newer methods of delivery of opiates for relief of pain

Abstract

Successful pain management using opiates requires both an analgesic with sufficient intrinsic activity and an effective administration system. Most instances of unsatisfactory pain control, however, are due to failure to achieve and maintain adequate blood concentrations of the chosen drug. Newer techniques of administration aim to overcome this problem. Oral opiate therapy with conventional or sustained-release formulations of morphine provide good control of terminal cancer pain provided that a regular dosing pattern is established and reviewed according to the patient's needs. This represents a significant departure from the traditional 'as required' prescription of this type of drug. In the management of acute severe pain, sublingual and intravenous opiates--self-administered as needed, or given by mandatory dosing schedules--have also been shown to overcome the limitations of intermittent intramuscular injections. A further novel development, stemming from basic neuroscience research, is the selective application of opiates to the spinal cord via the epidural or intrathecal route. This controversial technique has led to major improvements in treatment of some types of acute and chronic pain.