Clinical Medicine Reviews in Oncology

Breakthrough pain (BTP), defined as “transitory episodes of sudden severe pain that occur on a background of otherwise controlled pain” is common and disturbing for cancer patients. Optimal management of sudden, severe, and transitory episodes of BTP requires analgesics with rapid onset and short duration of effect, ideally in convenient and easily administered formulations. BTP has traditionally been treated with immediate-release oral opioids, but these analgesics are too slow in onset and have prolonged duration of effect. Recently developed and emerging pharmacotherapies exploit the properties of transmucosal absorption of lipophilic opioids in transbuccal, sublingual, and intranasal delivery systems to provide rapid and effective relief of BTP in reliable, convenient, and acceptable preparations.