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Changes to the ODG Drug Formulary will impact skeletal muscle relaxants

March 31, 2021 · Clinical Team

On March 31, 2021, the ODG Drug Formulary (Appendix A) will change the status of several medications, including, but not limited to, skeletal muscle relaxants (SMR). The SMRs, chlorzoxazone, metaxalone and tizanidine, in particular, will change 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. 

Understanding the ODG Drug Formulary  

A medication designated as a Y drug is typically preferred as a first-line treatment in ODG. Conversely, a medication designated as an N drug is non-formulary and may not be recommended as first-line treatment for an illness or injury. Additionally, pre-authorization may be required for non-Y drugs to determine medical necessity for the approved injury. Some states or payers may require a utilization review (UR) for N drugs per jurisdictional guidelines.

Impact on workers’ compensation and auto no-fault

Optum offers several formularies, including an ODG-based formulary. To maintain integrity of our ODG-based formulary, we review the published list from ODG on a scheduled and ad-hoc basis and perform impact analyses of the affected medications ― most recently, the skeletal muscle relaxants.

More information on ODG

A widely used resource in the workers’ compensation industry, ODG by MCG (formerly known as Official Disability Guidelines) provides independent, evidence-based medical treatment, disability and return-to-work guidelines for conditions commonly associated with workplace injury. They publish the ODG Drug Formulary as well, also known as Appendix A.

The ODG Drug Formulary includes medications approved by the U.S. Food and Drug Administration (FDA) that are often prescribed for the treatment of workers’ compensation injuries and provides information such as: therapeutic class, generic name, brand-name, generic or over-the-counter (OTC) availability, status and cost. The information also identifies and recommends cost-effective alternative to brand-name medications, first-line therapies and alternatives.  


How to use the ODG Drug Formulary

ODG state adoptions

If you have any questions, please contact your account manager, clinical liaison or our Clinical Services team at 1-877-275-7674 ext. 8612.


ODG by MCG [database online]. An MCG Health Company. Available at: Accessed March 17, 2021.

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