What is the appropriate treatment and follow-up for a patient with back spasms and a negative electrocardiogram (EKG) who is prescribed Flexeril (cyclobenzaprine)?

Management of Back Spasms with Flexeril (Cyclobenzaprine)

For a patient with back spasms and a negative EKG who has been prescribed Flexeril (cyclobenzaprine), use the medication for 7-14 days maximum at 5 mg three times daily, expect improvement within the first 3-4 doses, and follow up if symptoms persist beyond 2 weeks or worsen. 1

Medication Instructions for Flexeril (Cyclobenzaprine)

Dosing and Duration

• Take 5 mg by mouth three times daily (morning, afternoon, and evening) for acute muscle spasm relief 2
• Maximum treatment duration is 2-3 weeks because muscle spasm from acute painful conditions is typically short-lived and prolonged use lacks evidence of effectiveness 1, 3
• Expect relief within 3-4 doses (12-16 hours) of starting the medication 2
• The medication works best when combined with rest and physical therapy, not as a standalone treatment 1

Common Side Effects to Expect

• Dry mouth occurs in approximately 9% of patients and is the second most common side effect 3
• Drowsiness may occur but is less common with the 5 mg dose compared to higher doses 2
• Fatigue, dizziness, and sedation can occur but are typically mild 4

Important Safety Warnings

• Do not drive or operate machinery until you know how this medication affects you, especially during the first few days 2
• Avoid alcohol completely while taking this medication, as it increases drowsiness and sedation risk 5
• Do not take with other sedating medications without discussing with your provider 5
• This medication is not effective for nerve pain (radiculopathy) or chronic conditions—only for acute muscle spasm 3

When to Follow Up with Your Provider

Schedule Follow-Up If:

• Symptoms persist beyond 2 weeks of treatment, as this suggests the condition may not be simple muscle spasm and requires re-evaluation 1, 3
• Pain worsens or spreads to your legs, arms, or other areas 6
• New symptoms develop including numbness, tingling, weakness, or loss of bowel/bladder control (seek immediate care for these) 6
• Side effects become intolerable, particularly excessive drowsiness that interferes with daily activities 2
• No improvement after 4-7 days of treatment, as maximum benefit typically occurs early in the treatment course 7

Routine Follow-Up Timing

• Contact your provider at 1-2 weeks if symptoms have not substantially improved 6
• No routine follow-up is needed if symptoms resolve completely within 7-14 days 1

What to Expect from Treatment

Timeline for Improvement

• Days 1-4: Greatest treatment effect occurs during this period, with most patients reporting meaningful improvement 7
• By day 7: Approximately 88-93% of patients report at least mild improvement in pain and spasm 4
• After day 14: Treatment effect plateaus and continued use is not recommended 7, 3

Realistic Outcomes

• The medication provides modest but meaningful relief of muscle spasm, pain, tenderness, and improved range of motion 7
• Improvement is measured by reduced muscle spasm and associated symptoms including pain, tenderness, limitation of motion, and restriction in daily activities 1
• Cyclobenzaprine alone is as effective as combination therapy with ibuprofen for acute back pain with muscle spasm 4

Additional Self-Care Measures

Complementary Treatments

• Continue prescribed rest but avoid prolonged bed rest beyond 1-2 days 1
• Apply ice or heat to the affected area as tolerated
• Gentle stretching and movement as pain allows, progressing to physical therapy if recommended 1
• Over-the-counter pain relievers (acetaminophen or ibuprofen) can be used concurrently if needed 4

Red Flags Requiring Immediate Medical Attention

Seek Emergency Care If You Develop:

• Chest pain or pressure that returns, especially with exertion, sweating, or shortness of breath 6
• Severe or progressive weakness in legs or arms 6
• Loss of bowel or bladder control 6
• Fever with back pain, which may indicate infection 6
• Severe allergic reaction including rash, difficulty breathing, or swelling of face/throat 2

Why the Negative EKG Matters

Cardiac Clearance Context

• The negative EKG confirms that your symptoms are not cardiac in origin and supports the diagnosis of musculoskeletal back spasm 6
• This allows safe use of cyclobenzaprine without concern for underlying heart-related chest or back pain 6
• No cardiac follow-up is needed based on the negative EKG unless new cardiac symptoms develop 6

Medication Discontinuation

How to Stop Taking Flexeril

• No tapering is required for cyclobenzaprine when used for 2-3 weeks 1
• Simply stop taking the medication once symptoms resolve or after 2-3 weeks maximum 1
• Unlike benzodiazepines, cyclobenzaprine does not cause withdrawal symptoms or dependence at therapeutic doses 5