Transdermal Fentanyl for Pain Management in Cancer Patients

Abstract

Moderate to severe pain is common among cancer patients and affects 70–80 % of patients with advanced cancer. We have the means and the knowledge to relieve pain in many patients, but evidence from surveys and observational studies shows that many patients have troublesome or severe pain and do not get adequate relief. Although opioids remain the only class of drug with the ability to ameliorate severe pain, even in developed countries with access to a range of opioids, opioid formulations and adjuvant therapies, pain management is still a major problem in cancer care. As there is a narrow therapeutic window between pain control and toxicity, there is also substantial potential for side-effects, and, therefore, current practice when starting patients on fentanyl (an opioid class of drug) is to begin with a low dose and titrate the dose up slowly according to pain response and adverse events. As a consequence, it is often several days before a patient’s pain is controlled. Little is known about how factors such as patient demographics, organ function, effect of enzyme inhibitor/inducer, or the drug delivery system itself influence the pharmacokinetics (PK) of fentanyl in cancer patients. Better methods are required to monitor, individualise and improve opioid dosing.