Bronchitis, when will symptoms disappear?

My husband has been diagnosed with bronchitis and started on medication four days ago, he has two inhalers, some cough syrup and two types of tablets (deflazacort and moxifloxacin). He is still feeling very weak and still has a really bad cough. He is an ex smoker (quit almost 10 years ago). He's had pneumonia twice too and whenever he gets a cold it usually ends up in a chest infection that needs antibiotics. He's also got wheezing in his chest. Does anyone know how long it takes before bronchitis improves or when he might start to feel a bit better? Thanks!