PHOENIX, Arizona-Noncompliance with cancer therapy is going to become a very serious issue as more chemotherapy drugs become available in oral formulations, according to Deborah Boyle, RN, MSN, AOCN, FAAN. "The growth of oral chemotherapy is expansive," said Ms. Boyle, a practice outcomes nurse specialist with Banner Good Samaritan Regional Medical Center, Phoenix, Arizona. "I had an 'aha!' moment when discussing a patient with a radiation oncology colleague who specialized in breast cancer, when she posed the question, 'Has anyone ever thought of all the women who took adjuvant tamoxifen(Drug information on tamoxifen)-how do we know they took their pills as prescribed?"' Tamoxifen Adherence A recent investigation that addressed this issue (J Clin Oncol 21:602- 606, 2003) found that the mean level of adherence to tamoxifen was actually somewhat higher than for other medications; however, nearly 25% of patients were at risk for inadequate clinical response resulting from poor adherence. Overall adherence had fallen to about 50% in year 4 of tamoxifen therapy in this study, which was based on a review of prescription records for about 2,400 women enrolled in New Jersey Medicaid or pharmaceuticalassistance programs. "We are making all these assumptions about how to base our treatment decisions, prognosis, and further therapy, and we don't even know if those patients took their pills the way they should have," Ms. Boyle said. "This is a huge issue with overwhelming significance in the future." The literature contains little guid-ance for clinicians on the issue of medication adherence specifically in elderly cancer patients, Ms. Boyle said (J Natl Cancer Inst 94:652-661, 2002). However, some studies of medication adherence do suggest that when an older person takes four or more drugs routinely, the clinician should assume that at least one of them is not being taken as directed. The extent to which patients misunderstand medication use can be significant. Ms. Boyle shared one anecdote regarding a home-care nurse whoasked an elderly patient about a large bowl of prescription pills on his dining room table. The elderly man explained that the bowl contained all his medications for the day; every time he walked through the dining room, he would grab a handful and take them. "All he knew was these pills have to get in this body over a 24-hour period," Ms. Boyle said. "He could see no problem with his way of dealing with that ongoing demand." Two or More Medications Per Day In general, the elderly take two medications daily, most commonly cardiovascular, analgesic, or central nervous system drugs, according to data presented by Ms. Boyle (J Am Geriatr Soc 50:26-34, 2002). The highest prevalence of medication use is among women over 65 years of age; 23% take at least five prescription drugs daily, and 12% take 10 drugs daily. Implications of nonadherence incancer can be serious. For example, a nonadherent patient's condition could worsen as a result of inadequate drug consumption. As a consequence, that patient might then have to undergo unnecessary diagnostic testing and even hospitalization. Additionally, changes in the dose or regimen might be made unnecessarily. Problems of Nonadherence Cancer patients who are nonadherent may require more doctor visits, more hospitalizations, and longer lengths of stay when they are hospitalized. The value of clinical trials may suffer, as well: nonadherence could lead to misleading results, inconsistent response rates, and potentially erroneous dosing recommendations. "There are a myriad of problems that need to be identified," Ms. Boyle said, including:
- What risk factors are associated with nonadherence?
- How do cost, anxiety, and memory and hearing impairments affect adherence?
- What strategies improve adherence? Ongoing education? Written reminders? Phone follow-up? Memoryenhancing devices?