Taken Mobizox For Back Pain. Want Anti-inflammatory Medication

Hello. I am a 67 year old female, generally in good physical condition, tho I do take blood pressure medication . I fell and twisted my back 3 weeks ago. The left lower back went into spasm , such that it was difficult to sit or to sleep. A friend gave me some Mobizox, and I took half a tab at bedtime and was able to sleep. After a few days the pain was less so I stopped taking the Mobizox. But the pain never fully went away, my movements have been a bit limited and now my left upper back and shoulder tighten up. I am thinking to take more Mobizox as I think I do need an anti-inflammatory , but now I need to know the correct dosage and frequency, and how that might interact with my blood pressure med. Please advise me if you can. Thank you Ronnie