Dantrolene sodium: long-term effects in patients with muscle spasticity.

Seventy-seven patients with muscle spasticity secondary to central nervous system pathology were treated with dantrolene sodium for periods of up to two years. The drug was effective in reducing muscle spasms, clonus, muscle tone, and the force of muscle contraction elicited by Achilles tendon tap and tibial nerve stimulation, but improvement of function was seen less often. The incidence of side-effects was considerable, and poses a problem regarding patient acceptance of drug treatment.