What are the differences between Percocet (oxycodone/acetaminophen) and Norco (oxycodone/acetaminophen)?

Key Difference Between Percocet and Norco

The primary difference is the opioid component: Percocet contains oxycodone while Norco contains hydrocodone, but at equianalgesic doses they provide equivalent pain relief with no clinically significant differences in efficacy or safety. 1

Opioid Component and Potency

• Norco combines hydrocodone (typically 5–10 mg) with acetaminophen ≤325 mg per tablet 1
• Percocet combines oxycodone (typically 5–10 mg) with acetaminophen ≤325 mg per tablet 1
• Oxycodone is approximately 1.5 times more potent than hydrocodone on a milligram-to-milligram basis, meaning 10 mg hydrocodone roughly equals 6.7–7.5 mg oxycodone 1, 2

Clinical Efficacy: No Meaningful Difference

A prospective randomized trial directly comparing these medications found no differences in pain reduction, total doses taken, or overall efficacy assessments. 1 This is Level I evidence demonstrating that at equianalgesic dosing, the choice between these agents should not be based on perceived superiority of one over the other.

Common Pitfall to Avoid

Do not assume Percocet is intrinsically "stronger" solely based on its Schedule II status or reputation—efficacy is equivalent when proper dose conversions are applied. 1

Regulatory Classification

• Both hydrocodone-acetaminophen (Norco) and oxycodone-acetaminophen (Percocet) are currently Schedule II controlled substances 1
• Prior to 2014, Norco was Schedule III while Percocet was always Schedule II, but this regulatory difference no longer exists 1

Dosing and Administration

• Both agents are dosed every 4–6 hours as needed for acute pain 1
• Initial opioid dosing ranges from 5–15 mg of the opioid component for either medication 1
• The acetaminophen component is limited to ≤325 mg per tablet in both formulations 1

Dose Conversion Example

If converting from Norco 10-325 mg every 4 hours to Percocet, the equivalent would be approximately Percocet 7.5-325 mg every 4 hours, since 10 mg hydrocodone equals roughly 6.7–7.5 mg oxycodone 2

Safety Profile: Identical Acetaminophen Risk

• The risk of acetaminophen-induced hepatotoxicity is identical for both products given the same 325 mg acetaminophen content per tablet 1
• Total daily acetaminophen must not exceed 3,000–4,000 mg/day regardless of which product is used 3, 2
• Both carry similar risks of respiratory depression, dependence, and abuse as Schedule II opioids 2

Critical Safety Consideration

When prescribing either medication, avoid combination products in patients requiring large opioid doses to prevent acetaminophen-induced hepatic toxicity; instead, prescribe each medication individually at appropriate doses. 3

Prescribing Recommendations

• Limit prescriptions to the lowest effective dose for the shortest practical duration (≤1 week for acute pain) 1
• Neither should be prescribed routinely for chronic pain or acute exacerbations of chronic non-cancer pain 1
• Both medications provide synergistic analgesia through the combination of opioid and acetaminophen mechanisms 4, 5
• Consider these agents as part of multimodal analgesia to reduce individual opioid requirements 3

Bottom Line for Clinical Practice

The choice between Norco and Norco should be based on availability, formulary considerations, and patient-specific factors (such as prior response or side effects), not on assumptions about differential efficacy. 1 When converting between them, apply the 1:1.5 potency ratio (hydrocodone:oxycodone) and monitor for adequate pain control and adverse effects. 1, 2