The assessment and management of breakthrough pain in patients with cancer is pivotal to comprehensive pain and symptom management, and good cancer care. In this issue of Oncology Nurse Edition, Barton Bobb and Patrick Coyne have provided an excellent overview of breakthrough pain, with a focused challenge to oncology nurses to ramp up efforts to improve this deleterious and difficult-to-control problem. The authors have included a thorough description of breakthrough pain, key assessment tips, an overview of barriers that interfere with optimal control, and management strategies.

This commentary will continue to discuss the significance of managing breakthrough pain, with a focus on more comprehensive assessment and pharmacologic approaches, the mainstay of breakthrough pain management.

SIGNIFICANCE OF THE PROBLEM
The Cochrane review estimates the prevalence of breakthrough pain to range from 19% to 95%,[1] but many investigators indicate that the rate is closer to 64% to 86%.[2,3] Importantly, a recent survey by the American Pain Foundation underscored the magnitude of impact of this syndrome: it found 75% of patients responding viewed breakthrough cancer pain as one of the most challenging aspects of having cancer.[4] Furthermore, over half of the patients surveyed (53%) rated their pain as severe, or scoring an 8, 9, or 10 on a scale of 0–10, with 10 being the worst pain imaginable. The majority of patients also reported that pain wakes them from a deep sleep at least once per month (73%), affects their ability to perform household tasks (76%), and affects their desire to participate in some activities (83%).

CONDUCTING A MORE COMPREHENSIVE PAIN ASSESSMENT
The management of breakthrough pain begins with assessment, and pain assessment is a primary nursing responsibility. While many nurses have become skilled at screening patients for the presence of pain and then determining the intensity of pain according to a 0-to-10 scale, a more thorough assessment of pain that includes quality and temporal factors is imperative in addressing the problem of breakthrough pain. Pain quality assists in diagnosis of the specific pain syndrome (eg, nociceptive or neuropathic) so that coanalgesics can be individually tailored for each patient.[5] For example, anticonvulsants are helpful in management of neuropathic pain, and control of the underlying pain may indirectly control the breakthrough component of the pain. Asking about the temporal aspects of pain or the experience of pain over time focuses in on the characteristics of the individual pain experience.[6] The American Pain Foundation recommends the following temporal assessment questions:

• Do you have sudden, brief periods of increased pain (breakthrough pain)?

• How many episodes of this type of pain do you experience on a daily basis?

• Do certain activities cause the pain to occur or does the pain happen unpredictably?

• Which medicines do you take to manage this type of pain?

Nurses should keep these additional screening questions in mind and further investigate a positive response to any of them. For example, if the patient identifies specific activities that trigger the pain, further discussion about these activities with the patient is indicated, along with instruction about self-care strategies that can be employed by the patient. This information is often rolled into the individualized plan of care.

PHARMACOLOGIC MANAGEMENT OF BREAKTHROUGH PAIN
As indicated by Bobb and Coyne, assistive devices and other nonpharmacologic modalities are important in the management of breakthrough pain, but pharmacologic therapy is the mainstay treatment. Long-acting (LA) opioids provide around-the-clock coverage of pain and usually help with baseline control of pain and with associated breakthrough pain. Fishbain recommends that the LA dose be increased for appropriate pain management if the patient experiences four or more episodes of breakthrough pain per day,[7] but increasing the LA dose may medicate the patient beyond the breakthrough episode and contribute to untoward side effects such as sedation, depending on the characteristics of the breakthrough episode.

Fast-acting agents may be most appropriate for breakthrough pain, especially if the episodes are short. Therefore, knowledge of the pharmacokinetic properties of opioids is critical in addressing breakthrough pain. Intravenous opioids are one option if venous access is available. Most intravenous opioids peak within a few minutes, with fentanyl reaching its peak effect fastest. Transmucosal and buccal fentanyl are the fastest-acting orally administered opioids. Using these routes, some of the drug is absorbed in the oral cavity, while the remaining drug is swallowed and absorbed orally. In addition to the fast onset of action, fentanyl has a short half-life when given by this route; therefore, blood levels dissipate rapidly, preventing an accumulation of unwanted side effects. Three preparations of orally administered fentanyl are available: transmucosal fentanyl (Actiq), fentanyl buccal tablets (Fentora), and fentanyl buccal soluble film (Onsolis). More thorough review of these agents is available in the literature and within the prescribing guidelines of each agent.

In addition to opioids, coanalgesics provide another option for breakthrough pain. Nonsteroidal anti-inflammatory agents are helpful for bone-related pain. As previously mentioned, anticonvulsants are helpful in neuropathic pain, but other agents such as clonidine, tricyclic antidepressants, and local anesthetics may provide benefit. Corticosteroids are helpful for many pain syndromes.[8] Recently, a woman in my institution who had metastatic non–small-cell lung cancer with brachial plexopathy and severe incident pain was successfully managed with LA opioids, corticosteroids, lidocaine patches over the extremity, and transmucosal fentanyl. Overall, nurses are on the frontline in the assessment and management of breakthrough pain. A diligent individualized approach can help to ensure successful management of breakthrough pain and lessen the burden it adds to the cancer experience.