I haven't been able to control my asmath, i have been recently changed from symbicort to vaniar. and the predinose is the only thing good happening ?

Go to ER: Your asthma is recalcitrant to treatment with steroid/LABA. On Vannair, you can use 2 actuations every 12 hours of the 160/4.5, but you should also be using your rescue inhaler. Sounds like you need to have nebulizers ASAP and steroids. I suspect that you may have something else causing either asthma exacerbations or underlying issue that needs imaging/pulmonolgy ASAP. Please go to ER for eval

Asthma: A lot of management depends on other factors like smoking, environment, obesity, general health, and how you are using your rescue inhaler, slabutamol. you do not want to be on prednisone long term. Discuss with your GP.