Efficacy and tolerability of eperisone and baclofen in spastic palsy: a double-blind randomized trial

Introduction: Few trials have compared different central muscle relaxants in the treatment of spastic palsy. This head-to-head phase 3 trial compares oral eperisone, a central muscle relaxant with a promising activity in spasticity therapy, and oral baclofen. Methods: Patients (>18 years) with moderate to severe spastic palsy were eligible in this double-blind, randomized study; they received eperisone 300 mg/ day or baclofen 60 mg/day for 6 weeks. The efficacy evaluations included: functional analysis (Pedersen's scale, muscular tone, joint range of motion, 10-meter walking time); physiological and pathological reflexes; and electromyography (Hmax/Mmax amplitude ratio and the Wartenberg test). Physicians and patients globally assessed treatment efficacy. Results: Both eperisone (n=40) and baclofen (n=40) significantly improved functionality of lower limbs versus baseline (eperisone: -9.1%, P<0.01; baclofen: -8.3%, P<0.05), but only eperisone improved this parameter in the upper limbs (-7.8%, P<0.01 vs. -6.3%, P=NS). Both drugs reduced muscular tone from week 2. Only eperisone improved the joint range of motion (-32.5%, P<0.01 vs. -14.6%, P=NS). Both treatments reduced the 10-meter walking time (eperisone: -20.2%, P<0.01; baclofen: -24.0%, P<0.01); this effect was evident at week 2 with eperisone only. Both drugs improved reflexes. Eperisone and baclofen decreased the Hmax/Mmax amplitude ratio (eperisone: -30.0%, baclofen: -18.6%; P<0.01 for both). Eperisone increased the number of leg oscillations at the Wartenberg test (P<0.05) while baclofen increased the velocity of leg falling (P<0.01). For tolerability, no differences were observed between eperisone and baclofen in any parameters. Eperisone was judged as "good" by a higher number of physicians and patients than baclofen. Eighteen adverse events, most of mild intensity, were reported with eperisone and 27 with baclofen. Conclusion: Eperisone 300 mg/day and baclofen 60 mg/day, administered orally, are effective and well-tolerated drugs in the treatment of spastic palsy. However, eperisone might be associated with some additional clinical benefits when compared with baclofen.