How often do you need to take your non-steroidal inhaler? Non-steroidal inhalers need to be taken regularly every day for them to have an effect on the inflammation. However, they need to be taken more often than medication based preventers - up to three or four times a day on a regular basis. If you've been prescribed a non-steroidal inhaler, your GP or asthma nurse will tell you how often you need to take it. With any asthma preventer medicine, it's very important to get into a good routine of taking it as prescribed and discussed with your GP or asthma nurse.