Muscle relaxants
Short-term spasm relief
Muscle spasm from injury or back strain; baclofen and tizanidine also treat spasticity from neurologic conditions.
Acts on the central nervous system to reduce the signals that keep a muscle contracted.
The 4 muscle relaxants in the PTCB Top 200
| Generic | Brand | Common use |
|---|---|---|
| Cyclobenzaprine | Flexeril | muscle spasm |
| Tizanidine | Zanaflex | muscle spasticity |
| Baclofen | Lioresal | muscle spasticity |
| Methocarbamol | Robaxin | muscle spasm |
Tap any generic name for its full drug guide — brand↔generic, side effects, interactions and the exam tip.
What to know for the exam
- check_circleGenerally prescribed for short courses alongside rest and physical therapy.
- check_circleDrowsiness is the effect patients notice most.
- check_circleCyclobenzaprine is structurally related to the tricyclic antidepressants.
- check_circleBaclofen should be tapered rather than stopped abruptly.
These add to the sedation of alcohol, opioids and benzodiazepines — a real driving and falls risk, especially in older patients.
None of the oral muscle relaxants in the Top 200 are federally controlled.
Drill muscle relaxants the way the PTCE asks them
RxReflex groups the Top 200 drugs into classes like this one, then quizzes you on brand↔generic, class, side effects and interactions. Plus a guided Learn path, pharmacy math and 40+ cheat sheets. Free to start.
Frequently asked
What drugs are in the muscle relaxants class? add
Cyclobenzaprine, Tizanidine, Baclofen, Methocarbamol. All are in the PTCB Top 200.
What are muscle relaxants used for? add
Muscle spasm from injury or back strain; baclofen and tizanidine also treat spasticity from neurologic conditions.
How do muscle relaxants work? add
Acts on the central nervous system to reduce the signals that keep a muscle contracted.
Last reviewed August 7, 2026. For education only — not medical advice. Not affiliated with or endorsed by the PTCB.