Time to recovery in patients with acute painful musculoskeletal conditions treated with extended-release or immediate-release cyclobenzaprine.

INTRODUCTION: This post-hoc analysis examined time to recovery in patients with acute, painful musculoskeletal conditions following cyclobenzaprine extended release (CER; AMRIX(®), Cephalon, Inc., Frazer, PA, USA), cyclobenzaprine immediate release (CIR; Flexeril(®), Pliva, Pomona, NY, USA), or placebo administration. METHODS: Data were pooled from two identically designed, double-blind, placebo-controlled, parallel-group studies. Adults with acute, painful local muscle spasm were randomized to once-daily CER 15 mg, once-daily CER 30 mg, three-times-daily CIR 10 mg, or placebo for 14 days. Efficacy assessments were time to first rating of "a lot" or "complete" relief from local pain or restriction of movement and patient-rated medication helpfulness. RESULTS: A total of 504 patients were randomized, and 330 (65.5%) completed the studies. Median times to "a lot" or "complete" relief from local pain were faster with CER 15 mg (6 days, P=0.016), CER 30 mg (5 days, P=0.002), and CIR (5 days, P=0.002) versus placebo (8 days). Time to "a lot" or "complete" relief from restriction of movement was faster with CER 30 mg (5 days, P=0.004) and CIR (5 days, P=0.009) versus placebo (7 days). Median times to "very good" or "excellent" medication helpfulness were 10 days (CER 15 mg, P=0.020), 8 days (CER 30 mg, P=0.004), and 7 days (CIR, P<0.001) versus >14 days (placebo). Dry mouth, constipation, dizziness, headache, and somnolence were the most commonly reported adverse events. Somnolence rates were lower with CER 15 mg (0.8%, P=0.008) and CER 30 mg (1.6%, P=0.028) versus CIR (7.3%). CONCLUSION: Relief from local pain and restriction of movement occurred sooner with CER and CIR than placebo. CER was associated with less somnolence than CIR.

Efficacy and tolerability of cyclobenzaprine extended release for acute muscle spasm: a pooled analysis.

OBJECTIVE: To assess the efficacy and tolerability of once-daily cyclobenzaprine extended release (CER) 15 and 30 mg in relieving acute muscle spasm. METHODS: This is a pooled analysis of 2 randomized, double-blind, placebo-controlled, parallel-group studies of identical design. Adults with local muscle spasm associated with neck/low back pain were randomized to treatment with once-daily CER 15 (n = 127) or 30 mg (n = 126), cyclobenzaprine immediate release (CIR) 10 mg 3 times daily (n = 123), or placebo (n = 128) for 14 days. Primary outcome measures were the patient's rating of medication helpfulness and physician's clinical global assessment of response to therapy at day 4. RESULTS: Of 504 patients, 330 (65.5%) completed the studies. Significantly greater improvements in patient's rating of medication helpfulness were reported with CER 15 and 30 mg versus placebo at day 4 (P < 0.025). No differences were reported between groups in physician's clinical global assessment. Significantly greater improvements (P < 0.025) were noted in patient-rated secondary measures versus placebo: relief from local pain at days 4 (CER 30 mg) and 8 (CER 15 and 30 mg), global impression of change at days 4 and 8 (CER 30 mg), and restriction of movement at day 4 (CER 30 mg). Improvements with CER 15 and 30 mg on most efficacy measures were similar to CIR. There was less reported daytime drowsiness with CER 15 and 30 mg than with CIR (P < 0.05). Most adverse events (AEs) were mild in intensity. The most common AEs for all groups were dry mouth, constipation, dizziness, headache, and somnolence. The rate of somnolence reported as an AE was lower (P < 0.05) with CER 15 (0.8%) and 30 mg (1.6%) than with CIR (7.3%). CONCLUSION: Once-daily CER was effective in relieving acute muscle spasm based on patient's rating of medication helpfulness at day 4 and was generally well tolerated with a low rate of reported somnolence.

Cyclobenzaprine ER for muscle spasm associated with low back and neck pain: two randomized, double-blind, placebo-controlled studies of identical design.

OBJECTIVE: To evaluate efficacy and tolerability of once-daily cyclobenzaprine extended release (CER) 15- and 30-mg capsules in patients with muscle spasm associated with acute, painful musculoskeletal conditions. METHODS: Two identically designed, randomized, double-blind, placebo- and active-controlled, parallel-group studies in patients aged 18-75 years with muscle spasm associated with neck or back pain. Patients received CER 15 or 30 mg once daily, cyclobenzaprine immediate release (CIR) 10 mg three times daily, or placebo for 14 days. Primary efficacy measures were patient's rating of medication helpfulness and physician's clinical global assessment of response to therapy at day 4. Secondary measures were patient's rating of medication helpfulness and physician's clinical global assessment of response (days 8 and 14), relief from local pain, global impression of change, restriction in activities of daily living, restriction of movement, daytime drowsiness, quality of nighttime sleep (days 4, 8, and 14), and quality of life (days 8 and 14). RESULTS: A total of 156/254 randomized patients in study 1 and 174/250 in study 2 completed 14 days of treatment. Significant improvements in patient's rating of medication helpfulness were reported with CER versus placebo (CER 30 mg, study 1, p = 0.007; CER 15 mg, study 2, p = 0.018) at day 4. Significant improvements with CER 30 mg versus placebo were also seen at day 4 in study 1 for patient-rated global impression of change (p = 0.008), relief of local pain (p = 0.004), and restriction of movement (p = 0.002). Neither study reported differences between study groups on the physician's clinical global assessment. Improvements with CER were comparable to that of CIR. In both studies, daytime drowsiness was reported more frequently in active treatment groups than in the placebo group; however, reports of drowsiness decreased over time in all groups. In general, daytime drowsiness was reported more frequently in CIR groups than in CER groups. More adverse events were reported in the active treatment groups versus placebo and were similar in the CER and CIR groups, except somnolence, which occurred more frequently with CIR. CONCLUSIONS: Once-daily CER 15 mg (study 2) and CER 30 mg (study 1) were effective in treating muscle spasm associated with painful musculoskeletal conditions after 4 days of treatment. Differences between CER and placebo groups did not reach statistical significance on all efficacy measures, and the protocols were not powered to detect differences between active treatment arms. CER was generally safe and well tolerated, with low rates of somnolence.