Key takeaways
Cyclobenzaprine (Flexeril) and orphenadrine (Norflex) are both muscle relaxants used to relieve muscle pain and discomfort, but they have some differences. Cyclobenzaprine is available as both an immediate-release (IR) tablet and an extended-release (ER) capsule, while orphenadrine is available as an IR tablet, ER tablet, and an injection. Cyclobenzaprine works in the brain to relieve muscle spasms, whereas orphenadrine's exact mechanism is unclear but is thought to block nerve signals between the spinal cord and muscles. Cyclobenzaprine is typically taken three times a day for the IR form or once a day for the ER form, while orphenadrine is taken twice a day. Both medications can cause drowsiness and dry mouth, but cyclobenzaprine is has a higher risk of interactions with other medications that affect serotonin levels. Orphenadrine, on the other hand, is not recommended for people with certain conditions like glaucoma or heart problems. Both medications are available as lower-cost generics.
