Control of cancer pain often inadequate despite effective drugs and guidelines

Cancer patients continue to experience pain despite the availability of efficacious analgesic drugs and effective guidelines to treat cancer pain published by the World Health Organization. The reasons for uncontrolled pain are not clear. However, the development of new drugs, renewed interest in and new applications for already available drugs, and new strategies in pain therapy all hold promise for improved pain control. While morphine is the treatment of choice for severe cancer pain, adverse effects may limit treatment. Strategies such as switching treatment medications or changing the route of administration can sometimes be advantageous. Particular difficulties in patients with cancer include breakthrough pain and neuropathic pain. Breakthrough pain can be problematic in cancer patients even when baseline pain is under control; short-acting opioids are the mainstay of treatment. Neuropathic pain is a component of pain in up to 40% of cancer patients, but can usually be controlled with adjuvant drugs.