For spasm, you likely won't need to take them long enough to develop any kind of dependence. The spasm should resolve within a matter of days (if not less - sometimes hours). Dependence would typically take much longer.
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000556/

Depending on what kind of spasm it is (smooth muscle or skeletal) your doctor may prescribe either a muscle relaxant or antispasmodic (can ya b'lieve it? ). Some of the more common/often prescribed ones include Flexeril (cyclobenzaprine), Robaxin (Methocarbamol), and Soma (carisoprodol).

See also: http://en.wikipedia.org/wiki/Antispasmodic
See also: http://en.wikipedia.org/wiki/Muscle_relaxers

Supplements can help your body with resistance, but you can still get the occasional spasm, and if you do, I don't know that any supplement will release it, so it's probably be a good idea to have something from your doctor around anyway.

Google: spasm supplement

Doc