Tramadol to Percocet Dose Equivalence
100 mg of tramadol is approximately equivalent to 10-13 mg of oxycodone (the opioid component in Percocet), which translates to 1 to 1.5 tablets of Percocet 7.5/325 mg or approximately 1 tablet of Percocet 10/325 mg. 1
Conversion Rationale
The conversion is based on established opioid potency ratios from international pain management guidelines:
- Tramadol has a relative potency of 0.1-0.2 compared to oral morphine, meaning tramadol is approximately one-tenth as potent as morphine 1, 2
- Oxycodone (the active opioid in Percocet) has a relative potency of 2.0 compared to oral morphine, making it twice as potent as morphine 1
- Therefore, tramadol is approximately 10-20 times weaker than oxycodone 1
Practical Conversion Algorithm
Using the potency ratios:
- 100 mg tramadol ÷ 10 = 10 mg morphine equivalent
- 10 mg morphine equivalent ÷ 2 = 5 mg oxycodone minimum
- Using the upper range (0.2 potency): 100 mg tramadol ÷ 5 = 20 mg morphine equivalent ÷ 2 = 10 mg oxycodone
Start with Percocet 5/325 mg (1-2 tablets) or Percocet 7.5/325 mg (1 tablet) every 4-6 hours, not exceeding the acetaminophen limit of 4000 mg daily. 1, 3
Critical Safety Considerations
When converting from tramadol to Percocet, reduce the calculated equianalgesic dose by 25-50% initially to account for:
- Incomplete cross-tolerance between different opioid mechanisms 1
- Tramadol's dual mechanism (opioid + monoaminergic) versus oxycodone's pure opioid action 4, 5
- Individual variability in opioid metabolism and response 4
Monitoring Requirements
After conversion, assess within 24-48 hours for:
- Adequate pain control using numerical rating scales 2, 6
- Opioid-related adverse effects including sedation, respiratory depression, nausea, and constipation 1, 6
- Initiate prophylactic bowel regimen when starting Percocet, as constipation risk is higher than with tramadol 2, 6
Common Pitfalls to Avoid
- Do not use a 1:1 conversion ratio - this would result in severe overdosing given oxycodone's significantly higher potency 1
- Account for the acetaminophen component - Percocet contains 325-650 mg acetaminophen per tablet; ensure total daily acetaminophen does not exceed 4000 mg (or 3000 mg in elderly/hepatic impairment) 1, 3
- Avoid abrupt tramadol discontinuation if patient has been on it chronically, as tramadol has SNRI properties and sudden cessation may cause withdrawal symptoms beyond typical opioid withdrawal 4, 5
- Be cautious if patient was taking tramadol with serotonergic medications (SSRIs, SNRIs) - while this interaction is less relevant with pure opioids like oxycodone, reassess the overall medication regimen 2, 6