Improving the Safety of Opioid Use for Acute Noncancer Pain in Hospitalized Adults: A Consensus Statement From the Society of Hospital Medicine

Patients are often unaware of the risks of opioid therapy (see Consensus Statement 1 for key risks),²⁹ or that there are often equally effective alternative therapies. As with any therapy associated with substantial risk, clinicians should discuss these risks with patients and/or caregivers at the outset of therapy, as well as the potential benefits of nonopioid pharmacologic and nonpharmacologic therapies for managing pain. Patients should be informed that they may request nonopioid therapy in lieu of opioids, even for severe pain.

Once a Decision Has Been Made to Use Opioids During Hospitalization

5. SHM recommends that clinicians use the lowest effective opioid dose for the shortest duration possible.

Higher opioid doses are associated with an increased incidence of opioid-related adverse events, particularly overdose, in studies of both inpatient and outpatient populations.^{1,17,19,30,31} Studies in the inpatient and outpatient settings consistently demonstrate that risk increases with dosage.^19,30,31 Clinicians should reduce the usual starting dose by at least 50% among patients with conditions that increase susceptibility to opioid-related adverse events (see Consensus Statement 2). The ongoing need for opioids should be re-assessed regularly-at least daily-during the hospitalization, with attempts at tapering as healing occurs and/or pain and function improve.

6. SHM recommends that clinicians use immediate-release opioid formulations and avoid initiation of long-acting or extended-release formulations (including transdermal fentanyl) for treatment of acute pain.

Studies in outpatient settings demonstrate that the use of long-acting opioids is associated with greater risk for overdose–especially in opioid-naïve patients–and long-term use.^32,33 Further, hospitalized patients frequently have fluctuating renal function and rapidly changing pain levels. We therefore recommend that initiation of long-acting opioids be avoided for the treatment of acute, noncancer pain in hospitalized medical patients. It is important to note that although we recommend avoiding initiation of long-acting opioids for the treatment of acute, noncancer pain, there are circumstances outside of the scope of this Consensus Statement for which initiation of long-acting opioids may be indicated, including the treatment of opioid withdrawal. We also do not recommend discontinuation of long-acting or extended-release opioids in patients who are taking these medications for chronic pain at the time of hospital admission (unless there are concerns regarding adverse effects or drug–disease interactions).

7. SHM recommends that clinicians use the oral route of administration whenever possible. Intravenous opioids should be reserved for patients who cannot take food or medications by mouth, patients suspected of gastrointestinal malabsorption, or when immediate pain control and/or rapid dose titration is necessary.

Intravenous opioid administration is associated with an increased risk of side effects, adverse events, and medication errors.^34-36 Additionally, studies demonstrate that in general, the addiction potential of medications is greater the more rapid the onset of action (the onset of action is 5–10 min for intravenous and 15–30 minutes for oral administration).^37,38 Furthermore, the duration of action is greater for oral compared to that of intravenous administration, potentially allowing for more consistent pain relief and less frequent administrations. As such, intravenous administration should be reserved for situations when oral administration is not possible or likely to be ineffective, or when immediate pain control and/or rapid titration is necessary.

8. SHM recommends that clinicians use an opioid equivalency table or calculator to understand the relative potency of different opioids 1) when initiating opioid therapy, 2) when changing from one route of administration to another, and 3) when changing from one opioid to another. When changing from one opioid to another, clinicians should generally reduce the dose of the new opioid by at least 25%–50% of the calculated equianalgesic dose to account for interindividual variability in the response to opioids as well as possible incomplete cross-tolerance.

Most errors causing preventable adverse drug events in hospitals occur at the ordering stage.^39,40 Clinicians are often unaware of the potency of different types of opioids relative to each other or to morphine (ie, morphine equivalent dose), which can lead to inadvertent overdose when initiating therapy with nonmorphine opioids and when converting from one opioid to another. To facilitate safe opioid use, we recommend that clinicians use one of several available opioid equivalency tables or calculators to better understand the relative potencies of opioids and to inform both starting dose calculations and conversions between opioids and routes of administration. When converting from one opioid to another, we caution clinicians to reduce the dose of the new opioid by at least 25%–50% of the calculated equianalgesic dose to account for interindividual variability in the response to opioids and the potential for incomplete cross-tolerance, wherein tolerance to a currently administered opioid does not extend completely to other opioids. Clinicians should use extreme caution when performing conversions to and from methadone and consider consultation with a hospital pharmacist or a pain management specialist, when available, to assist with conversion decisions and calculations.