For an otherwise healthy adult with acute shoulder pain and no liver disease, opioid dependence, or acetaminophen contraindications, how often and at what dose should Percocet (oxycodone/acetaminophen) be taken?

Percocet Dosing for Acute Shoulder Pain

For an otherwise healthy adult with acute shoulder pain, prescribe Percocet (oxycodone 5 mg/acetaminophen 325 mg) one to two tablets every 4–6 hours as needed—not on a scheduled basis—for a maximum of 7 days, with a daily limit of 8 tablets to avoid exceeding 2,600 mg of acetaminophen. 1

Dosing Strategy

• Start with the lowest effective dose: oxycodone 5 mg/acetaminophen 325 mg, one to two tablets every 4–6 hours as needed (PRN), not around-the-clock 2, 1.
• Maximum daily limit: 8 tablets per day to stay well below the 4,000 mg acetaminophen threshold (8 tablets = 2,600 mg acetaminophen) 2, 1.
• Duration: Prescribe only for the expected duration of pain severe enough to require opioids—typically no more than 1 week for acute musculoskeletal injuries 1.

Why "As Needed" Dosing for Acute Pain

• The CDC and emergency medicine guidelines explicitly recommend PRN (as needed) dosing rather than scheduled dosing for acute pain to minimize unnecessary opioid exposure and reduce risks of dependence 2, 1.
• Scheduled dosing is reserved for chronic pain or cancer pain where continuous analgesia is required to prevent pain recurrence 1.
• For acute shoulder pain, PRN dosing allows the patient to titrate to their pain level and avoid taking opioids when pain is tolerable 1.

First-Line Therapy Considerations

Before prescribing Percocet, consider whether nonopioid alternatives are appropriate:

• Acetaminophen alone (1,000 mg every 6 hours) or oral NSAIDs (e.g., ibuprofen 600 mg every 6 hours) provide comparable pain relief for many acute musculoskeletal injuries with fewer adverse effects 2.
• High-certainty evidence shows acetaminophen plus opioids reduce pain by only 0.5 cm more than acetaminophen alone on a 10-cm scale at <2 hours—a clinically marginal benefit 2.
• Topical NSAIDs (e.g., diclofenac gel) are also effective for localized shoulder pain and avoid systemic side effects 2.

When Opioids Are Justified

• Reserve Percocet for moderate to severe pain (≥6/10 on pain scale) that is not controlled or unlikely to be controlled with acetaminophen or NSAIDs alone 2.
• One study showed that among patients with acute musculoskeletal pain refractory to ibuprofen 600 mg, oxycodone 10 mg/acetaminophen 650 mg provided 1.1 units more pain relief than acetaminophen alone (95% CI 0.3–1.9), but 34% experienced adverse events versus 9% with acetaminophen alone 3.

Acetaminophen Safety

• Calculate total daily acetaminophen intake from all sources (prescription and over-the-counter) to prevent hepatotoxicity 2, 1.
• The FDA recommends a maximum of 4,000 mg/day, but the NCCN suggests limiting chronic use to ≤3,000 mg/day due to hepatotoxicity concerns 2.
• For acute use (<14 days), 4,000 mg/day is generally safe in healthy adults without liver disease 4.
• Each Percocet tablet contains 325 mg acetaminophen, so 8 tablets = 2,600 mg—well within safe limits 2, 1.

Opioid-Related Adverse Effects

• Common side effects include nausea, constipation, dizziness, and sedation 2.
• Prescribe a prophylactic laxative (e.g., senna, docusate) to prevent opioid-induced constipation 1.
• Warn patients about sedation and avoid driving or operating machinery 2.

Critical Pitfalls to Avoid

• Do not prescribe scheduled (around-the-clock) dosing for acute pain—this is appropriate only for chronic or cancer pain 1.
• Do not exceed 7 days of opioid therapy for acute shoulder pain; longer durations increase risk of long-term disability and dependence 2.
• Do not combine Percocet with additional acetaminophen products (e.g., Tylenol, cold medications) without accounting for total daily acetaminophen dose 2, 1.
• Do not prescribe opioids as first-line therapy when nonopioid alternatives (acetaminophen, NSAIDs) are likely to be effective 2.
• Do not fail to reassess pain and opioid need frequently; reduce or discontinue if pain improves 1.

Alternative Dosing for Severe Pain

• If pain is severe (≥8/10) and refractory to lower doses, consider oxycodone 10 mg/acetaminophen 325 mg every 4–6 hours as needed, but this increases adverse effects significantly 3.
• The evidence suggests that lower doses (5 mg oxycodone) are effective for most patients with moderate pain and reduce treatment-related adverse reactions 5.

Monitoring and Follow-Up

• Reassess pain within 24–48 hours to determine if opioids are still needed or if nonopioid alternatives can be substituted 1.
• If Percocet is used for more than a few days, taper gradually rather than abruptly discontinuing to avoid withdrawal symptoms 1.
• Implement routine monitoring including patient-provider agreements, urine drug testing (if prolonged use), and prescription drug monitoring program checks 1.