It depends on what type of muscles you want relaxed...different drugs work on different types of muscles.

The function of the muscle depends on the type of medication that works best. That's how it was described to me by my internist and ortho doc. If it's an inflammation type problem, sometimes a simple OTC medication will work.

Spasms can be handled with different types of medications, such as Soma or Tizanadine or valium. For instance, bladder spasms are handled for me by a small dose of valium. I use Soma for spasticity and vicodin for back spasms and pain.

So, I guess there is no simple answer to your broad, general question. You should be evaluated by a doctor.