What is the next course of action when a patient taking oxycodone (OxyContin) 10-325 milligrams (mg) for pain management, under the supervision of a pain management specialist, requests cyclobenzaprine (Flexeril) from a primary care physician?

Coordination with Pain Management Specialist is Essential Before Prescribing

As the primary care physician, you should contact the patient's pain management specialist to coordinate care before prescribing cyclobenzaprine, as this patient is already on opioid therapy and adding a centrally-acting muscle relaxant requires careful risk assessment and unified treatment planning. 1

Immediate Steps to Take

1. Verify Current Opioid Regimen and Pain Management Plan

• Contact the pain management specialist to discuss the cyclobenzaprine request and confirm the current opioid dosing (oxycodone 10-325 mg) 1
• Determine if the patient's pain management plan already includes muscle relaxants or if this represents a new symptom requiring evaluation 1
• Calculate the patient's current morphine milligram equivalent (MME) daily dose—oxycodone has 1.5x the potency of morphine, so this calculation is critical for risk stratification 2

2. Assess the Clinical Indication for Cyclobenzaprine

• Determine if the patient has acute muscle spasm (neck or low back pain) that would justify cyclobenzaprine use 3, 4
• Cyclobenzaprine is indicated for acute painful musculoskeletal conditions with muscle spasm, typically for short-term use (7-14 days) 3, 5
• If the patient has been on opioids chronically, evaluate whether this represents inadequate pain control that should be addressed by the pain specialist rather than adding another medication 1

Risk Assessment Before Prescribing

Central Nervous System Depression Risk

• The combination of opioids and cyclobenzaprine significantly increases sedation risk 1, 6
• Cyclobenzaprine causes sedation through potent non-competitive antagonism of central histamine H1 receptors, with >30% of patients experiencing drowsiness 6
• When combined with opioids, this creates additive CNS depression that increases fall risk, respiratory depression risk, and impairs driving ability 1

Check for Additional Risk Factors

• Verify the patient is not taking benzodiazepines, as opioid-benzodiazepine combinations have disproportionate overdose death rates 1
• Assess for age ≥65 years, renal/hepatic insufficiency, sleep-disordered breathing, or mental health comorbidities—all increase opioid-related risks 1
• Review the prescription drug monitoring program (PDMP) to identify any undisclosed controlled substances 1

If You Decide to Prescribe Cyclobenzaprine

Dosing Recommendations

• Prescribe cyclobenzaprine 5 mg three times daily rather than 10 mg three times daily—the 5 mg dose is equally effective with significantly less sedation (0.8% vs 7.3% somnolence rate) 3, 5
• Limit the prescription to 7-14 days for acute muscle spasm 3, 4
• Cyclobenzaprine monotherapy at 5 mg TID is as effective as combination therapy with ibuprofen for acute neck/back pain with muscle spasm 4

Patient Education and Safety Precautions

• Explicitly warn the patient about increased drowsiness and sedation when combining cyclobenzaprine with oxycodone 1, 6
• Advise against driving or operating machinery until they know how the combination affects them 1
• Instruct the patient not to use alcohol or other sedating substances 1
• Provide naloxone and overdose prevention education, especially if the patient's total MME approaches or exceeds 50 MME/day 1

Follow-Up Requirements

• Schedule a follow-up within 3-7 days to assess efficacy and monitor for excessive sedation 3, 4
• Discontinue cyclobenzaprine after the acute episode resolves (typically 7-14 days) 3, 5
• Communicate with the pain management specialist about the prescription and the patient's response 1

Critical Pitfalls to Avoid

• Do not prescribe without coordinating with the pain specialist—this creates fragmented care and increases the risk of polypharmacy complications 1
• Do not prescribe cyclobenzaprine 10 mg TID—the 5 mg dose has equivalent efficacy with substantially less sedation 3, 5
• Do not provide long-term or refillable prescriptions—cyclobenzaprine is indicated only for acute muscle spasm (7-14 days maximum) 3, 4
• Do not ignore frequent requests for additional medications—this may signal inadequate pain control requiring reassessment by the pain specialist rather than medication stacking 1

Alternative Approach: Refer Back to Pain Management

If the patient's pain is not adequately controlled or if they are requesting additional medications frequently, the most appropriate action may be to refer them back to their pain management specialist rather than adding cyclobenzaprine yourself 1. This ensures:

• Comprehensive reassessment of the pain management plan 1
• Evaluation for whether opioid dose adjustment is needed rather than adding another centrally-acting medication 1
• Unified treatment approach that avoids medication conflicts 1