Hello, thanks for using health care magic Most often, runny nostrils and sore throat are due to a viral infection. Most viral infections produce low grade fever with watery colourless nasal discharges associated with muscle pains. Antibiotics are not indicated in such cases unless there is a bacterial super-infection. Bacterial super-infection or bacterial infection presents with yellowish nasal discharges with considerable fever. Antibiotics are indicated in such cases. Azithral is the commercial name of the antibiotic azithromycin which is an advance generation of macrolide. It is a potent antibiotic and very effective in upper respiratory tract bacterial infection. Generally, 1 tablet of azithromycin 500 mg is effective in adults with moderate weight like yours. However, there is no much difference in side effects with a two tablets of 500mg. You should consider re-discussing with your doctor but 500mg is effective. Best regards Dr Achuo