My Son Is 8 Years Old. He Always Have Respiratory

My son is 8 years old. He always have respiratory issues during change in weather. This time his cough took a long to settle down due to climatic conditions.ha already had a complete dose of advent 625mg for 5 days. He had wheezing , for which doctor advised to use nebulization. Have always avoided its use as i think it will make his body dependent on the nebulizer once starts using. Please suggest.