A cough that isn't responding to an antibiotic like Cefixime often points to a viral or allergic cause rather than a bacterial one, so it isn't something to panic about. The newer medicines prescribed today usually take 2 to 3 days to show real improvement, not overnight.
Next Steps
For tonight, try warm fluids, a spoon of honey if you tolerate it, and sleeping with your head slightly raised to ease the coughing. Steam inhalation before bed can also help loosen the irritation.
Health Tips
Please go back to your doctor sooner if you develop breathlessness, high fever or blood tinged phlegm, or if the cough hasn't eased within 3 days.