Flare-up:
For the random spasm or ache, grab some Tylenol. "Most acute back pain is not inflammatory, so for many people, taking an analgesic like acetaminophen may be all they need," says Portenoy. When this doesn't work, then try an NSAID.

You need something stronger:
When you're in agony or the discomfort doesn't relent in several days, ask your doctor about a combination drug such as Tylenol with codeine, a prescription NSAID, or a short-acting opioid. Drugs for chronic back pain include antidepressants, antiepileptics, muscle relaxants such as cyclobenzaprine (Flexeril), and long-acting opioids like OxyContin.