Hello Doc..my Child Is 1 Yr 6 Months Old. He

Hello Doc..my child is 1 yr 6 months old. He is having cough since last 1 month (on and off types). He is not eating anything ..just having milk (mother's feed or formula feed ) and water. Doctor has prescribed Nebulizer apart from few medicines (Montair, Livolin, Alegra). I am not sure if Nebulizer is safe for little ones ? I have heard that if given once, in future child will be habitual and everytime in cough nebulizer will be required ..
Please suggest. Thanks a lot.