Prescription of opioids for opioid-naive medical inpatients.

BACKGROUND: Harms associated with prescription opioids are a major and increasing public health concern. Prescribing of opioids for inpatients may contribute to the problem, especially if primary care practitioners continue opioid therapy that is initiated in hospital.

OBJECTIVES: To describe the extent and nature of opioid prescribing for opioid-naive patients (i.e., no use of opioids within 2 weeks before admission) on an internal medicine unit.

METHODS: This single-centre study involved chart review for opioid-naive patients admitted to the internal medicine unit of a large academic health sciences centre in Toronto, Ontario. Over 12 weeks, patients were prospectively identified for the study, and charts were later reviewed to characterize opioid use during the hospital stay and upon discharge. The primary outcomes were the proportions of opioid-naive patients for whom opioids were prescribed in hospital and upon discharge. Data on serious adverse events related to opioid use (e.g., need for naloxone or occurrence of falls) were also collected through chart review.

RESULTS: From July 4 to September 22, 2011, a total of 721 patients were admitted to the study unit, of whom 381 (53%) were classified as opioid-naive. Opioids were prescribed for 82 (22%) of these opioid-naive patients while they were in hospital. Among the opioid-naive patients, there were a total of 247 opioid prescriptions, with hydromorphone (110 prescriptions) and morphine (92 prescriptions) being the drugs most commonly prescribed. For 23 (28%) of the patients with a prescription for opioids in hospital (6% of all opioid-naive patients), an opioid was also prescribed upon discharge. The indication for opioids was documented in 16 (70%) of the 23 discharge prescriptions. No adverse events or deaths related to opioid use were identified during the hospital stays.

CONCLUSIONS: Among opioid-naive patients admitted to the internal medicine unit, opioids were prescribed for about 1 in 5 patients, and less than one-third of these patients were continued on opioids at the time of discharge. These results, if replicated elsewhere, suggest that efforts to improve opioid prescribing and reduce attendant harm should be focused primarily on the outpatient setting.