Cefdinir
"Had sinus infection. Dr. Prescribed cefdinir , got a shot, and prednisone.  3 days of treatment with cefdinir, no better and feeling worse. Lethargic, dizzy. Stopped cefdinir and started getting better. 2 days later I break out in horrific, painful itching  hives on my entire body !!! ER visit. Steroid shot and hydroxyzine 2 days and still suffering unbearable pain and itching! Saw my GP today. She 's never ever seen allergic reaction this severe! Just have to wait it out and in meantime SUFFER!!! Do not use this drug!"