Is it appropriate to switch a patient from oxycodone (immediate release) 5 mg every 4 hours to OxyContin (oxycodone extended release) 10 mg twice daily, with breakthrough oxycodone 5 mg every 8 hours as needed, for uncontrolled pain?

Inappropriate Conversion: Proposed Regimen Contains Critical Dosing Errors

The proposed conversion to OxyContin 10 mg twice daily with breakthrough oxycodone 5 mg every 8 hours PRN is inappropriate and contains multiple serious errors that violate established opioid prescribing principles.

Critical Problems with the Proposed Regimen

Problem 1: Inadequate Baseline Opioid Dose

• The patient is currently taking oxycodone 5 mg every 4 hours, which equals 30 mg total daily dose (6 doses × 5 mg) 1
• The proposed OxyContin 10 mg twice daily provides only 20 mg total daily dose, representing a 33% reduction in baseline opioid coverage 1
• This is backwards dosing for a patient with uncontrolled pain—you are decreasing the total daily opioid dose when pain control is already inadequate 1

Problem 2: Incorrect Breakthrough Dosing Interval

• The proposed breakthrough oxycodone every 8 hours PRN violates fundamental opioid prescribing principles 2
• Breakthrough doses should be available every 1-2 hours for oral immediate-release opioids, not every 8 hours 2, 3
• The European Association for Palliative Care explicitly states that rescue doses can be offered "up to hourly" for oral administration 2

Problem 3: Incorrect Breakthrough Dose Calculation

• The breakthrough dose should be 10-20% of the total 24-hour opioid requirement 3
• For a patient requiring 30 mg daily, the appropriate breakthrough dose would be 3-6 mg (10-20% of 30 mg), not 5 mg every 8 hours 3
• When converting to extended-release formulations, the breakthrough dose should equal approximately one-sixth of the total daily dose (equivalent to the 4-hourly dose) 2

Correct Approach to This Clinical Scenario

Step 1: Calculate Current Total Daily Opioid Requirement

• Current regimen: oxycodone 5 mg every 4 hours = 30 mg/day 1
• Since pain is not well controlled, the patient likely needs more than 30 mg/day, not less 1

Step 2: Appropriate Conversion to Extended-Release

• Convert the total daily dose to OxyContin: 30 mg daily = OxyContin 15 mg every 12 hours 1
• The FDA label explicitly states that conversion from immediate-release to extended-release oxycodone "must be accompanied by close observation for signs of excessive sedation and respiratory depression" 1
• For uncontrolled pain, consider increasing the total daily dose by 25-50% rather than maintaining or decreasing it 1

Step 3: Prescribe Appropriate Breakthrough Medication

• Breakthrough dose: oxycodone immediate-release 5 mg (approximately one-sixth of 30 mg daily dose) 2, 3
• Frequency: every 1-2 hours as needed, not every 8 hours 2, 3
• Patients on stable extended-release opioids require continued access to rescue doses for breakthrough pain 2

Step 4: Titrate Based on Breakthrough Use

• If the patient requires more than 2-3 breakthrough doses per day, this indicates inadequate baseline coverage 3
• Calculate total opioid consumption (scheduled plus all PRN doses) over 24 hours to determine the new baseline requirement 3
• Increase the around-the-clock extended-release dose accordingly 3, 1

Specific Recommendation for This Patient

Prescribe OxyContin 15 mg every 12 hours (or consider 20 mg every 12 hours given inadequate pain control) with oxycodone immediate-release 5 mg every 1-2 hours as needed for breakthrough pain. 1, 3

• This maintains the current 30 mg total daily dose as a minimum baseline 1
• Monitor closely for the first 24-72 hours after conversion 1
• Reassess after 48 hours and adjust the extended-release dose based on breakthrough medication use 3, 1

Critical Pitfalls to Avoid

• Never reduce the total daily opioid dose when converting a patient with uncontrolled pain 1
• Never restrict breakthrough dosing to every 8 hours—this creates unnecessary suffering and violates established guidelines 2, 3
• Extended-release opioids like OxyContin are contraindicated for acute pain and should only be used in opioid-tolerant patients requiring around-the-clock analgesia 2
• The 2012 ACEP guidelines explicitly warn that "long-acting or extended-release schedule II products such as oxycodone ER (OxyContin)...should not be used for acute pain" 2