My wife is 68 yrs old and has fibromyalgia. She has been taking the antibiotic Clindamycin for the past 8 days for a tooth infection. After supper she was sitting at the table and suddenly she got very dizzy. I helped her to the couch and after a glass of water and reclining for a few minutes she is feeling better. She was recently diagnosed with Sjogren s Syndrome. What can cause a sudden dizzy spell.