What is the best treatment for bronchitis, my boy is 6years old and i don't want to use antibiotics unless it's absolutely necessary.

Patience: Most bronchitis is at least initially a virus & supportive measures like rest and good nutrition do wonders.A percentage will eventually become contaminated by airway bacteria and transition to a bacterial infection.These clear quicker with antibiotics & could evolve into pneumonia. Many would self heal as they did before we had antibiotics but would remain ill longer and at risk for complications