A Study to Evaluate Two Formulations of Carisoprodol in Subjects With Musculoskeletal Spasm of the Lower Back

Methodology: This was a randomized, double-blind, double-dummy, placebo-controlled, parallel-group study in subjects 18-70 years of age with acute, painful, muscle spasm of the lower back. The study consisted of a baseline screening (Study Day 1), during which subjects were evaluated for inclusion/exclusion criteria, and a 7-day double-blind treatment period (Study Day 1 through Study Day 7). Subjects were randomly assigned to be dosed twice daily with one of the following double-blind treatments: sustained release(SR) carisoprodol 500-mg tablets,sustained release (SR) carisoprodol 700-mg tablets, or placebo. Subjects were evaluated in the clinic on Study Days 1, 3 and 7. Subjects who remained symptomatic on Study Day 7 were allowed to continue in the study for a 7-day, double-blind extension period at the discretion of the Investigator. Subjects were contacted by telephone for a safety follow-up 7 days after the last dose of study medication. A pharmacokinetic (PK) substudy was conducted at selected sites. These sites obtained blood samples for PK analysis at the end of the 7-day treatment period and the 14-day treatment period, if applicable.