Strategies for the Treatment of Cancer Pain in the New Millennium

Abstract

As was the case in the era before us, in the new millennium we will continue to see an abundance of patients experiencing cancer-related pain for different reasons. Although much needless pain and suffering still affects many of those with cancer, we are presented with a medical dichotomy. With the analgesic drugs available today, and the relatively simple and effective guidelines to treat cancer pain published and disseminated by the World Health Organization, why do people with cancer continue to experience pain? As we search for the answer, the horizon may hold promising new drugs, 'old drugs' with new interest and applications, and new strategies for the field of pain therapy. Possibilities include the isolation and development of analgesics or analgesic combinations that may minimise the adverse effects which are often associated with the current therapeutic class of opioid analgesics. In addition, current research points to promising results identifying the N-methyl D-aspartate non-opioid receptor as a likely component of neuropathic pain. Drugs such as gabapentin, the mechanism of action of which is not well known, have found favour within the clinical community for their analgesic properties and good tolerability. Methadone, in a phase of resurgence, has garnered the attention of the clinical community because of its unique receptor activity and pharmacoeconomic benefits. A number of clinical studies have demonstrated that methadone has a valuable role in treating cancer pain. Perhaps, an unbalanced focus on the risks of inappropriate use, rather than the benefits, should not compromise or distract from the use of methadone as an alternative to morphine. Studies are on going to assess the potential role of methadone in treating neuropathic pain. Drugs such as cannabinoids, although currently applicable for patients with anorexia, nausea and/or vomiting, may offer benefits to patients experiencing pain. Other opportunities exist with such compounds as alpha2-adrenergic agonists, nicotine, lidocaine and ketamine. New strategies such as the switching opioids and/or their route of administration may offer improved analgesia with fewer adverse effects, thus providing therapeutic alternatives for the clinical community. In addition, there is interest in the co-administration of opioids that act on different receptors. For instance, oxycodone appears to be a kappa opioid receptor agonist and may offer enhanced analgesia when combined with morphine.

Influence of Opioid Agonists on Cardiac Human Ether-a-go-go-related Gene K+ Currents

“…Moreover, in the past several years, high-dose i.v. administration of methadone has been gaining popularity for the alleviation of chronic pain (Ayonrinde and Bridge, 2000; Ripamonti and Dickerson, 2001;Bruera and Sweeney, 2002). Methadone is generally used to treat cancer pain when other opioids are not effective and, therefore, its substitution with another opioid drug may be problematic (Manfredi et al, 1997;Santiago-Palma et al, 2001).…”

Comparison of sustained-release morphine with sustained-release oxycodone in advanced cancer patients

“…Although both drugs have been used regularly, each drug has been individually evaluated, and as a final result, each patient has normally used either morphine or oxycodone alone (Heiskanen and Kalso, 1997;MucciLoRusso et al, 1998;Heiskanen et al, 2000;Klepstad et al, 2003). Among the strategies for the treatment of cancer pain, there is interest in the coadministration of opioids that act on different receptors (Heiskanen et al, 2000;Ripamonti and Dickerson, 2001). For instance, the antinociceptive effect of morphine and the semisynthetic opioid oxycodone appears to be mediated preferentially at m and k receptors, respectively (Ross and Smith, 1997;Nielsen et al, 2000), and oxycodone may offer enhanced analgesia when combined with morphine.…”

Pain Management for Urological Cancer Patients in Palliative Care

“…Oncological neuropathic pain syndromes are some of the most challenging cases that a pain management physician will encounter. Therefore, recognition of the syndrome is of paramount importance [36][37][38]. The impaired activity of patients with severe neuropathic pain represents an enormous strain; psychological changes frequently occur and specific therapeutic intervention is required.…”