Question 575: Does using an asthma inhaler break your fast? It’s a puff of medicine that you breathe into your lungs.
Answer 575: Since, the puffer uses a compressed gas that is used by the patient, which reaches the lungs via the trachea to expand the lungs, is not food or drink or anything resembling them there would be no problem for a person observing fast to use asthma inhaler during the day. His fast is not broken by using this kind of medicine, according to all maraja’.[1]
Note: There are many kinds of medication for asthma, some of which invalidate the fast and some do not. The most well-known of these medicines and treatments are puffers, oxygen, vaporizers and capsules that do not break the fast.
For further information in this regards, please read the following answers:
Index: Things from which a person keeping fast must abstain & Kaffarah (Expiation), answer 372.
Index: Number of things which are disapproved (Makruh) for a person observing fast, answer 566.
[1] . Tawzih al-Masael (annotated by Imam Khomeini), Vol. 1, Pg. 892, Issue: 1576; Ibid, Pg. 893, Sistani; The official website of the office of Sayyid Sistani (ha), Dialogue on miscellaneous issues.