I went to a walk in clinic with extreme sinus congestion, and stuffy ears, and was diagnosed with sinusitis, and given 250 mg of ceftin to take twice a day. I am on day 5 of ceftin, and athough my sinus congestion has improved some, my throat on the right side now burns and has a white patch on it and is red. Could this be viral? Does ceftin take this long to work?