Following a bout of pneumonia that would not resolve after 2 courses of treatment with Augmentin, a bronchoscopy was done and large amts of pus were washed out of my lungs. I was also diagnosed with a chronic case of sinuisitis. My pulmonologist prescribed BIAXIN XL, 2 x 500mg daily, as followup to my lung problems and to treat the chronic sinuisitis. I am supposed to take Baxin for 6 weeks. Yes, I repeat 6 weeks!!! After the first week of treatment, I developed severe leg cramps. I informed my doctor and he prescribed quinine sulfate for my leg cramps. The quinine seemed to help the leg cramps at first, however, I have now been on Baxin for 3 weeks and the leg cramps are recurring, but worse. They have caused loss of sleep & I seem to be quite restless Since I haven't had leg cramps in the last 5 years, and since they began once on Baxin, I can't help but believe this side effect is due to the antiobiotic.