Oxycodone vs Dilaudid (Hydromorphone) for Pain Management
Choose oxycodone as the first-line strong opioid for moderate to severe pain, reserving hydromorphone for patients who cannot tolerate morphine or oxycodone, or those with renal impairment. The evidence demonstrates equivalent analgesic efficacy between these agents, but hydromorphone carries a higher burden of adverse effects, particularly diarrhea and sedation.
Primary Recommendation Based on Guidelines
Oral morphine remains the gold standard first-choice opioid for moderate to severe cancer pain, with oxycodone and hydromorphone serving as effective alternatives 1. However, when choosing specifically between oxycodone and hydromorphone:
- Oxycodone should be preferred over hydromorphone for initial strong opioid therapy 1
- Hydromorphone showed no evidence of superior effectiveness over oxycodone in systematic reviews of nine RCTs, yet adverse effects such as diarrhea and sedation were more common with hydromorphone 1
- Pain scores were no different between patients receiving oxycodone versus hydromorphone (pooled standardized mean difference 0.04, P=5.8), though pain scores were actually lower for oxycodone compared with hydromorphone 1
When to Choose Hydromorphone Over Oxycodone
Hydromorphone becomes the preferred choice in specific clinical scenarios:
- Renal impairment: Hydromorphone is extensively metabolized via glucuronidation in the liver with minimal unchanged drug excreted in urine, making it potentially safer than morphine (though not specifically compared to oxycodone) in renal dysfunction 2
- Poor tolerance to morphine or oxycodone: Hydromorphone serves as a first-line alternative when these agents are not tolerated 2
- Need for opioid rotation: Consider switching to hydromorphone when patients develop intolerable side effects to other opioids 2
Practical Dosing Considerations
Oxycodone
- Available in both immediate-release and modified-release formulations 1, 2
- Relative potency approximately 1.5 times that of oral morphine 3
- Can start with low doses (5 mg every 12 hours) for opioid-naïve patients 4
Hydromorphone
- Also available in immediate-release and modified-release oral formulations 1, 2
- Relative potency approximately 5-7.5 times that of oral morphine 2
- When converting from oral to parenteral hydromorphone, divide the dose by 2-3 to achieve equianalgesic effect 2
- Rescue doses typically calculated as 10-15% of total daily dose 2
Administration Route Priority
- Oral route should be the first choice for both agents 1, 2
- For severe pain requiring urgent relief, parenteral administration (subcutaneous or intravenous) can be used for either agent 1, 2
- Start with immediate-release formulations for dose titration, then transition to modified-release formulations for maintenance 2
Critical Safety Considerations
Both agents require identical safety precautions:
- Assess potential risks and benefits when initiating long-term opioid therapy 1
- Incorporate universal precautions to minimize abuse, addiction, and opioid-related deaths 1
- Exercise caution when coprescribing other centrally acting drugs, particularly benzodiazepines 1
- Laxatives must be routinely prescribed for prophylaxis and management of opioid-induced constipation 1
- Prescribe rescue doses for breakthrough pain episodes 1
Common Pitfall to Avoid
The most significant pitfall is choosing hydromorphone first-line without a specific indication. While both agents have comparable efficacy, hydromorphone's higher adverse effect profile (particularly diarrhea and sedation) makes it less favorable as initial therapy 1. Reserve hydromorphone for situations where oxycodone or morphine have failed or are contraindicated, or when renal impairment is a concern.