Otherwise healthy person. Was on Biaxin XL 1000mg once a day for 10 days for sinus infection. Had 2-3 second long vibration feeling over heart every 4-5 minutes after about 3 days of drug and continued until 2 days after 10 day course completed. Had diarrhea and weird taste in mouth. Now (10 days after Biaxin course was completed) have fatigue, low WBC for no apparent reason. Not sure if related.