Difficulty swallowing - covid patient.

Hi, My brother tested covid +ve 5 days back. He is suffereing with throat pain while swallowing  from day one. Now it became severe that he is not able to take fluids also properly. He is feeling like something got stuck in the throat. He is able to swallow fluids little bit from left side of throat only with much difficulty. He is also experiencing severe pain from left side of throat to ear while swallowing. Is this due to covid or any other reason. Please help me regarding this as he is becoming weak day by day as he is unable to eat and drink. Currently we are using this medicine: 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 + Vit C, zincovit, B complex, Vit D( weekly once)