With evidence indicating that overprescription of opioids has contributed to the current opioid epidemic, current Society of Hospital Medicine (SHM) guidelines recommend using the oral route of administration whenever possible—reserving intravenous (IV) administration for patients who cannot take food or medications by mouth, those suspected of gastrointestinal malabsorption, or when immediate pain control and/or rapid dose titration is necessary—given increased risks of side effects, adverse events, medication errors, and addiction with IV compared with oral formulations. IV opioids are also directly and indirectly (nursing time and equipment) more expensive that oral and can lead to avoidable complications like patient discomfort, infection, and thrombophlebitis.
Despite the SHM recommendation, Amber Moore, MD, and colleagues observed that IV opioids were being overprescribed and continued longer than clinically indicated in patients in the hospital setting for a number of reasons.
For a study published in the Journal of Hospital Medicine, Dr. Moore and colleagues sought to identify the incidence of potentially inappropriate IV opioid use in hospitalized patients “in order to show that physicians have the potential to decrease misuse by more appropriately prescribing opioids,” says Dr. Moore. The researchers reviewed the charts of 200 hospitalizations during February 2007 with any order for IV opioids using pharmacy charge data.
Defining Inappropriate Use
Based on SHM recommendations, potentially inappropriate use of IV opioids was defined as use for greater than 24 hours in patients who could receive oral medications—as evidenced by receipt of other orally administered medications during the same 24 hours—and was not mechanically ventilated. The 24-hour window was chosen based on the typical ability to determine opioid needs and transition to an oral regimen within that timeframe in patients without contraindications following initial immediate pain control with IV opioids when indicated. IV doses after 24 hours were considered potentially inappropriate except in patients with nil PO status, including medications. IV opioids for respiratory distress were considered appropriate.
Patients with an active cancer diagnosis, who had chosen comfort measures only, or with GI dysfunction were excluded from the study, as IV opioids beyond 24 hours may be appropriate in these populations. Days spent receiving opioids by patient-controlled analgesia (PCA) or continuous IV drop were excluded, given the difficulty in identifying the appropriate time to transition from PCA to IV or PO opioids.
One-Third of Patients
Among the predominantly Caucasian study population with an average age of 56.3 years, the majority were on a surgical service and were mostly commonly administered hydromorphone. Significant differences were observed between the opioid types in the percentage of doses considered inappropriate, with the highest proportion seen with morphine (44.6%), followed by hydromorphone (27.4%), and fentanyl (2.6%).
“Inpatient physicians, on both surgical and medicals services, overprescribed IV opioids,” explains Dr. Moore. “Our study found that 31% of patients were administered at least one potentially inappropriate opioid, and 33% of IV doses were considered potentially inappropriate. Given the strict definition used in our research, we suspect that over-prescribing is even more common than our numbers suggest.”Significant associations between potentially inappropriate IV opioid administration and age, sex, or admitting service were not observed (Table).
The need exists, according to Dr. Moore for more research examining how to improve opioid prescribing practices, as well as for quality improvement initiatives to be studied and disseminated to provide better understanding of how to best improve adherence to guidelines. “Physicians have the potential to decrease the risks of IV opioids by improving prescribing practices and choosing oral opioids over IV whenever appropriate,” she says. “We hope this study encourages physicians to examine their own prescribing practices and ultimately decrease use of inappropriate IV opioids.”
Potentially Inappropriate Use of Intravenous Opioids in Hospitalized Patients