Difficulty swallowing- covid +ve patient

Hi, My brother got tested +ve for covid 5 days back. He is in home isolation and we are using below medication: 1. Tab Favicovid 400:      1st day:  4 - 4      From 2nd to 7th day: 2 - 2       After food 2. Tab Nise : 1-1-1 for 3 days    after food 3. Cap Pantop DSR:1-1 before food 4. Tab Allegra 180: 1-1for 5 days 5. Tab Ceftum 500: 1-1 for 5 days after food 6. Zincovit, vit c, vit d(weekly once) From past 5 days(from day one when he tested positive) he is suffering from throat pain. From last 2 days it became severe and he is unable to swallow even fluids properly. He is feeling like something got stuck up in the throat and only able to swallow little bit from left side only with some difficulty. He is also  getting ear pain on left side while swallowing. Is this due to covid only or is there any other reason for this?