A PHARMACOLOGICAL COMPARISON OF THERAPEUTICALLY USEFUL CENTRALLY ACTING SKELETAL MUSCLE RELAXANTS

¹ Department of Pharmacology, Division of Medical Sciences, McNeil Laboratories, Incorporated, Philadelphia, Pennsylvania

A group of six clinically useful centrally acting skeletal muscle relaxants were compared by a series of pharmacological testing procedures for determination of relative potency, duration of action and type of activity these agents display.

Zoxazolamine and chlorzoxazone appeared to be the most potent agents in inducing paralysis especially by the parenteral route. Meprobamate was a potent paralytic drug when administered orally.

All the drugs tested with the exception of mephenesin were relatively long-acting compounds.

Anticonvulsant studies carried out with these drugs indicate that chlorzoxazone possesses potent anti-strychnine activity while having virtually no protective action against pentylenetetrazol. Meprobamate displays potent anti-pentylenetetrazol activity and has relatively weak protective potential against strychnine. This suggests that chlorzoxazone may act principally at spinal levels and meprobamate at supraspinal levels.