What Are The Side Effects Of Flexeril?

I have 5 budging disc with very bad back spasms. Have been on Flexeril , taking only 10 mg in the evening for several years. Flexeril makes me very sleepy the next day until almost 4-5 pm. Sometimes by back locks up and I can't stand up. Flexeril doesn't seem to release the spasm. Friend is taking Baclofen and it is helping her without being sleepy the next day. Should I try Baclofen ??