Can I start a continuous hydromorphone (Dilaudid Contin) infusion in a patient who is not achieving adequate analgesia with fentanyl?

Switching to Hydromorphone in Patients with Inadequate Fentanyl Analgesia

Yes, you can and should initiate hydromorphone (including continuous infusion) in patients not achieving adequate pain control with fentanyl—this is a standard opioid rotation strategy recommended when the current opioid fails to provide adequate analgesia despite dose escalation. 1

Rationale for Opioid Rotation from Fentanyl to Hydromorphone

• When an opioid fails to provide adequate analgesia or causes unmanageable adverse effects, it should be discontinued and a different opioid should be offered. 1

• Opioid switching (rotation) is the process of substituting one opioid for another to improve the opioid response, either by improving pain relief or by reducing the intensity of adverse effects. 1

• There is no evidence that one sequence is better than another, so rotating from fentanyl to hydromorphone is equally valid as any other rotation sequence. 1

• Hydromorphone is specifically recommended as a preferred agent for acute IV pain control in patients already on fentanyl therapy, with a faster onset of action compared to morphine, making it effective for severe pain requiring rapid titration. 2

Specific Clinical Scenarios Supporting This Rotation

For Acute IV Pain Management on Top of Fentanyl Pumps

• Start with IV hydromorphone 0.015 mg/kg administered slowly over 2-3 minutes, with repeat boluses available every 15 minutes as needed. 2

• If two boluses are required within one hour, initiate a continuous hydromorphone infusion at 0.5-1 mg/hour. 2

• Account for existing fentanyl exposure by calculating breakthrough dosing as 10-20% of the total 24-hour opioid requirement. 2

For Complete Opioid Rotation from Fentanyl to Hydromorphone

• Calculate the total 24-hour fentanyl requirement and convert using equianalgesic ratios. 1

• Reduce the calculated equianalgesic dose by 25-50% to account for incomplete cross-tolerance between opioids. 1, 3

• For reference: 25 mcg/hr transdermal fentanyl equals approximately 8 mg oral hydromorphone per day. 2

Dosing Protocol for Hydromorphone Initiation

Intramuscular/Subcutaneous Route

• The usual starting dose is 1-2 mg every 2-3 hours as necessary. 4

Intravenous Route

• The usual starting dose is 0.2-1 mg every 2-3 hours, given slowly over at least 2-3 minutes. 4

• For continuous infusion after achieving initial control: start at 0.5-1 mg/hour and titrate based on response. 2

Dose Adjustments for Organ Dysfunction

• In hepatic impairment: initiate treatment with one-fourth to one-half the usual starting dose, depending on degree of impairment. 4

• In renal impairment: initiate treatment with one-fourth to one-half the usual starting dose, depending on degree of impairment. 4

Critical Advantages of Fentanyl-to-Hydromorphone Rotation

• Rotation from fentanyl to hydromorphone (or vice versa) can resolve neuroexcitatory side effects that may develop with prolonged high-dose morphine-like opioids, as these structurally dissimilar opioids have different metabolic profiles. 5

• Hydromorphone does not produce the problematic 3-glucuronide metabolites that morphine does, which can cause allodynia, myoclonus, and seizures at high doses. 5

• Case reports demonstrate successful resolution of intrathecal hydromorphone-induced peripheral edema by rotating to fentanyl, and the reverse rotation (fentanyl to hydromorphone) is equally valid for inadequate analgesia. 6

• Hydromorphone appears to be a potent analgesic with similar efficacy to morphine and an adverse effect profile comparable to other mu opioid receptor agonists. 7

Mandatory Safety Monitoring

• Continuous pulse oximetry is mandatory for all patients receiving IV opioid boluses on top of baseline fentanyl therapy. 2

• Have naloxone immediately available at 0.1 mg/kg IV, which may be repeated every 30-60 seconds. 2, 4

• Serious, life-threatening, or fatal respiratory depression may occur, especially during initiation or following a dosage increase—proper dosing and titration are essential. 4

• Reassess pain scores every 15 minutes after each IV bolus using standardized pain assessment tools. 2

• Concomitant use of opioids with benzodiazepines or other CNS depressants may result in profound sedation, respiratory depression, coma, and death—reserve concomitant prescribing only when alternative treatment options are inadequate. 4

Adjuvant Strategies to Optimize Outcomes

• Multimodal analgesia with IV acetaminophen 1000 mg every 6 hours and IV ketorolac 15-30 mg every 6 hours can reduce total opioid consumption and adverse effects. 2

• Regional anesthesia should be considered when anatomically feasible and not delaying emergency care. 2

• Maintain short-acting opioid rescue medication available during the transition period. 1

Critical Pitfalls to Avoid

• Never use a simple mathematical calculation alone for conversion—this must be part of a comprehensive assessment evaluating the underlying clinical situation, pain intensity, adverse effects, comorbidities, and concomitant drugs. 1

• Do not forget the 25-50% dose reduction when rotating between opioids to account for incomplete cross-tolerance. 1, 3

• Adjust the basal fentanyl pump rate only after acute pain is controlled and based on total rescue medication requirements over 24-48 hours, not immediately. 2

• Avoid rapid IV administration of hydromorphone—always give slowly over 2-3 minutes to prevent respiratory complications. 4

• Hydromorphone should be prescribed only by healthcare professionals knowledgeable about opioid use and how to mitigate associated risks. 4