Gaps in the Use of Long-Acting Opioids Within Intervals of Consecutive Days Among Cancer Outpatients Using Electronic Pill Caps.

OBJECTIVE: This study describes individual cancer patients' nonuse of extended-release or long-acting (ER/LA) opioids, including periods of gap between opioid doses taken.

DESIGN: Secondary analysis of a three-month observational study of prescribed ER/LA opioids monitored using electronic pill caps.

SETTING: Two outpatient oncology clinics of a large health system in the Mid-Atlantic region.

PARTICIPANTS: Inclusion was based on self-identified African Americans and whites, at least 18 years old, diagnosed with solid tumors or multiple myeloma. For the current analysis, the additional inclusion criterion was prescription of an oral ER/LA opioid for cancer pain to be taken around the clock.

METHODS: The electronic monitoring period for each study participant was partitioned into intervals of days between days with one or more openings (using medication event monitoring systems) representing rates of ER/LA opioid nonuse over consecutive days and over time.

RESULTS: Of the sample (N = 109), two-thirds of the cancer patients had some nonuse of prescribed ER/LA opioids, with one in four having nonuse during 31.5-87.5% of their electronic-monitoring periods. Nonuse over periods of five or more, six or more, and seven or more consecutive days occurred for 37.6%, 34.9%, and 30.3% of the participants, respectively.

CONCLUSIONS: About one in three ambulatory cancer patients in this study had substantial gaps between days of ER/LA opioid use, potentially resulting in risk of overdose depending upon the prescribed ER/LA opioid type, dose, and length of the time the opioid was stopped and resumed at the previous dose. This phenomenon has received little to no attention in the opioid safety discourse.