Answered by Shaykh Faraz Rabbani
Is it allowed to use an asthma pump during the Fast?
Answer:
In the Name of Allah, Most Merciful and Compassionate.
Walaikum assalam wa rahmatullah,
If one has a genuine medical need for an asthma pump that cannot be otherwise fulfilled, then it would be permitted to use it. However, it would invalidate the fast and require that the fast be made up later. This is because anything that has a perceptible body breaks the fast if it enters the body through a normal channel. [Shurunbulali, Maraqi al-Sa`adaat; Rafi Usmani, Dabit al-Muftirat]
And Allah alone gives success.
Wassalam,
Faraz Rabbani