Lowest Dose of OxyContin
The lowest available dose of OxyContin (controlled-release oxycodone) is 10 mg, administered twice daily (every 12 hours). 1
Available Formulations
OxyContin is marketed in controlled-release tablets of 10 mg, 20 mg, 40 mg, and 80 mg for twice-daily administration. 2 The tablets must be swallowed whole and must not be broken, chewed, or crushed, as this would destroy the controlled-release mechanism and could result in rapid release and absorption of a potentially fatal dose. 2
Initial Dosing Considerations
For opioid-naive patients, the FDA-approved starting dose is 10 mg every 12 hours. 1, 2 However, there are critical caveats:
- OxyContin is indicated only for chronic pain requiring around-the-clock opioid therapy and should NOT be used for acute pain. 3
- Extended-release oxycodone products like OxyContin should only be used in patients who are already opioid-tolerant. 3
- Long-acting formulations are not intended for use as "as-needed" analgesics. 3
Important Clinical Context
When OxyContin is Inappropriate
If a patient is opioid-naive and requires opioid therapy, immediate-release oxycodone (OxyNorm) should be used instead, starting at 5-15 mg every 4-6 hours as needed. 1 This allows for safer titration and assessment of opioid tolerance before considering conversion to extended-release formulations.
Conversion to OxyContin
When converting from immediate-release oxycodone to OxyContin, the relative bioavailability is not fully established, requiring close observation for excessive sedation and respiratory depression. 1 The general principle is to calculate the total daily dose of immediate-release oxycodone and divide it into two equal doses for twice-daily OxyContin administration.
Special Populations
No dose reduction is needed in elderly patients or those with moderate hepatic or renal failure when initiating the 10 mg dose. 2 However, patients with end-stage liver disease should avoid oxycodone entirely, as recent guidelines recommend paracetamol, morphine, and hydromorphone instead. 4
Pharmacokinetic Advantages
OxyContin's controlled-release formulation provides several benefits over immediate-release preparations:
- Effect onset occurs within 1 hour with duration of 12 hours. 2
- Stable plasma levels are reached within 24 hours (compared to 2-7 days for morphine). 2
- Plasma half-life is 3-5 hours, making titration more predictable than morphine. 2
Critical Safety Warning
Monitor patients closely for respiratory depression, especially within the first 24-72 hours of initiating therapy, even at the lowest 10 mg dose. 1 The risk is particularly elevated in opioid-naive patients, which is why OxyContin should be reserved for opioid-tolerant individuals.