Budesonide inhaler is a steroid inhaler that helps to reduce and prevent swelling and inflammation in the lungs. Budesonide inhaler is normally referred to as a ‘controller’ inhaler as it helps to control symptoms such as breathlessness in asthma or chronic obstructive pulmonary disease (COPD). COPD is a disease affecting the lungs which makes it harder for the person to breathe as the disease gets worse.
For controller inhalers with dose counter, check the dose counter and change the canister once the dose counter indicates zero  doses.
For controller inhalers without dose counter, mark the date of opening and based on the dosing regimen, throw away when the doses are used up.