Changes to the status of several medications including skeletal muscle relaxants in the ODG prescription drug formulary will likely have an impact in states that include the formulary in their treatment guidelines, Optum Workers’ Comp and Auto No-Fault said Wednesday.

The ODG formulary designates medications that are preferred as first-line treatment options as “Y” drugs. Medications designated as an “N” drug are not recommended as the first-line treatment. Some states require prior authorization for N drugs only, while others require pre-authorization for anything not designated as a “Y” drug.

Skeletal muscle relaxants, including chlorzoxazone, metaxalone and tizanidine, are changing from a “Y” drug to an “N” drug.

“In states following the ODG drug formulary for their workers’ compensation claimants’ medication treatments, a shift in the utilization of these medications is expected,” Optum said.