Cefalaxin is good antibiotic but yo must first get him examined by ENT specialist
and get done Flexible fiberoptic naspharyngo-laryngoscopy
done to see for the condition of the vocal cords .
As you said he has husky voice so the vocal cords (where the vibration
occurs so that a person can speak)needs to be examined to see for proper movement.
If movement is decreased for one vocal cord then he needs to be given some steroid
medication and further evaluation is also required.
You must also take antiinflammatory medicines also