What is the appropriate short‑term dosing of cyclobenzaprine hydrochloride 7.5 mg oral tablets for adults, and how should the dose be adjusted for elderly or patients with hepatic or renal impairment?

Cyclobenzaprine HCl 7.5 mg Oral Tablet Dosing

For adults with acute muscle spasm, cyclobenzaprine 7.5 mg should be administered three times daily (TID), though the 5 mg TID regimen is equally effective with significantly less sedation and is preferred for most patients, particularly the elderly. 1

Standard Adult Dosing

• The typical adult dose is 5-10 mg three times daily for acute painful musculoskeletal conditions with muscle spasm 1, 2
• Treatment duration should be limited to 7 days, as cyclobenzaprine is indicated only for short-term use in acute conditions 1, 2
• The 5 mg TID regimen provides equivalent efficacy to 10 mg TID with a lower incidence of sedation, making it the preferred starting dose 1
• Onset of relief occurs within 3-4 doses of the 5 mg regimen 1

Elderly Patients (≥65 Years)

Elderly patients should receive reduced doses due to altered hepatic and renal function that changes drug pharmacokinetics. 3

• Start with 5 mg TID maximum in elderly patients, as this population experiences more pronounced cholinergic adverse effects 3
• The 2.5 mg TID dose was not significantly more effective than placebo and should be avoided 1
• Pharmacokinetic studies in patients aged 65-75 years demonstrate similar systemic exposure to younger adults, but tolerability concerns warrant lower dosing 3

Hepatic Impairment

Patients with hepatic impairment require dose reduction due to extensive hepatic metabolism of cyclobenzaprine 3

• Use the lowest effective dose (5 mg TID) and monitor closely for adverse effects
• Consider further dose reduction or increased dosing intervals in moderate to severe hepatic dysfunction

Renal Impairment

Dose adjustment is recommended in renal impairment due to altered drug clearance 3

• Start with 5 mg TID and titrate cautiously based on response and tolerability
• Monitor for accumulation of active metabolites in moderate to severe renal dysfunction

Key Safety Considerations

• Sedation and dry mouth are the most common dose-related adverse effects, occurring in 54-62% of patients on 5-10 mg doses versus 35% on placebo 1
• Efficacy is independent of sedation—patients who do not experience somnolence still demonstrate meaningful treatment effects 1
• Cyclobenzaprine monotherapy at 5 mg TID is as effective as combination therapy with ibuprofen (400 mg or 800 mg TID), so adding NSAIDs provides no additional benefit 2
• Adverse events are the primary reason for treatment discontinuation in the 5-10 mg dose groups 1

Clinical Pitfalls to Avoid

• Do not use the 2.5 mg TID dose—it lacks efficacy compared to placebo 1
• Do not prescribe for longer than 7 days—these studies only evaluated short-term use for acute conditions 1, 2
• Do not automatically add NSAIDs—cyclobenzaprine 5 mg TID alone is equally effective as combination therapy 2
• Do not use standard adult doses in elderly patients—start with 5 mg TID maximum due to pharmacokinetic changes 3