If both Flexiril and Robaxin are both muscle relaxers how do they differ in the way they work?

Felxeril relieves skeletal muscle spasm of local origin without interfering with muscle function. Robaxin works by blocking nerve impulses (or pain sensations) that are sent to your brain.

What will happen with your husband taking one of each depends on the dosages and how his body responds to the medications. He should call his doctor and ask them if he needs to do anything special since he took both of them. The two medications have similar side effects, so the extra dosage could lead him to experience more of the side effects from the medications.