In advanced cancer, up to about half of all patients undergoing palliative anticancer treatment experience pain [1
]. Yet, for many patients, cancer-related pain is often undertreated [15
This case study presents data relating to 2 cancer patients undergoing palliative care who successfully received higher than currently recommended maximum dosages of transdermal buprenorphine for pain management. The highest dosage of transdermal buprenorphine used in these 2 patients was 210 and 175 μg/h, respectively. The observation that adequate pain control, with minimal adverse effects, was achieved in these 2 patients, who received transdermal buprenorphine up to 210 µg/h, supports the hypothesis that dose titration of transdermal buprenorphine above 140 µg/h can be clinically effective and well tolerated.
The observation of pain control with transdermal buprenorphine up to 210 µg/h also challenges the assumption of a buprenorphine ceiling effect in the clinical setting, in line with an expert panel opinion relating to the analgesic action of transdermal buprenorphine [5
]. Indeed, despite the fact that a ceiling effect was reported in several preclinical animal models with buprenorphine [5
], a consensus group agreed that buprenorphine behaves as a full µ-opioid agonist for analgesia and that a ceiling effect is only clinically relevant for respiratory depression (thus reducing the likelihood of this potentially fatal adverse event) [5
]. However, as the current anecdotal evidence is only based on experience obtained with 2 patients in a non-interventional setting, it would benefit from confirmation in an interventional clinical trial setting (large prospective cohort studies, for example), with a larger sample size. Moreover, another potential limitation of the current case study is the fact that, in the absence of an objective way of assessing pain, treatment success was assessed through subjective evaluation by the healthcare practitioner and patient.
Consensus criteria for selecting analgesics for the treatment of cancer pain were recently reviewed by an expert panel and, although efficacy (which is dependent on whether the pain is of nociceptive, neuropathic or mixed origin) is the most important factor, other aspects include individualized treatment to suit the patient, cultural influences (e.g. fear of opioid use), pain intensity, comorbidities, ease of titration and dose flexibility, and knowledge of pretreatment [15
]. The general failure to control cancer pain can possibly be attributed to poor control of the neuropathic component. Transdermal buprenorphine has demonstrated a beneficial analgesic effect in patients with chronic neuropathic, nociceptive and cancer-related pain [13
In summary, we describe 2 patients undergoing palliative cancer treatment who received successful analgesic medication with transdermal buprenorphine at doses up to 210 μg/h. Whilst we acknowledge that these clinical observations are based on only 2 patients and, therefore, should not be overstated, these findings provide initial evidence that transdermal buprenorphine >140 μg/h could provide effective pain relief and is well tolerated. A clinical study to confirm these initial observations is warranted.