Decades ago The World Health Organisation outlined the use of a stepwise approach or "analgesic ladder" to manage pain in cancer patients (1). The main tenet is to initiate treatment with less potent analgesics early and to advance to more potent analgesics with concomitant use of adjuvant drugs and invasive procedures as pain intensifies. Some researchers estimate that 5 to 15% of cancer pain patients will have inadequate control of pain with orally administered medications mainly in advanced and terminal stages of the disease (2,3). Pain specialists should be capable of using alternative pain-relieving modalities and based on the clinical situation select the adequate techniques. First of all a difficult task is to identify patients, who will benefit for a given modality as those choices are often made in patients presenting complex clinical pictures. When oral opioid therapy combined with adjuvant analgesics is consistently incapable of producing adequate analgesia and possibly elicit toxicity a number of interventions lend themselves as alternatives. Regarding the opioids, generally three options can be explored: 1) change of drug (opioid rotation), 2) change of route, and 3) change of drug and route. The latter option can be achieved by continuous transdermal, intravenous and subcutaneous administrations or by spinal/epidural infusions via implantable devices. These options will be discussed in more details.

References
1. World Health Organization. Cancer Pain Relief. Geneva: World Health Organisation, 1986.
2. Staats P. Neural infusion for pain control: When, why, and what to do after the implant. Oncology 13: 58-62, 1999.
3. Meuser T, Pietruck C, Radbruch L, Stute P, Lehmann KL, Grond S. Symptoms during cancer pain treatment following WHO-guidelines: a longitudinal follow-up study of symptom prevalence, severity and etiology. Pain 93: 247-257, 2001.