As-Salamu `alaykum:

The reasoning about the inhalator would apply to cigarettes as well, over which there is consensus that they break the fast. The allowance of intramuscular and intraveinous medications is similar to the allowance of eyedrops, i.e. eyes and veins are not considered to be among the normal openings of the body (although, even in the latter perspective, certain tooth and gum medications have been allowed--an inhalator dispensation might go the same route, not sure). Contrariwise, it has also been replied that injections do break the fast if consisting in sedative, or glucose.

1. Whether or not muftis anywhere--and not just in Pakistan--have "very rudimentary and inadequate understanding of modern medical issues" should not distract us from the fact that a foreign substance (jawhar) that is wilfully brought through the mouth from outside the body into the inside (jawf) of the body breaks the fast, whether in solid, liquid or gaseous form. You yourself have conceded that the medicine "is inhaled into the lungs" and the latter are an internal organ. Hence the response given by the Hanafi Fiqh teacher Shaykh Wahbi Sulayman Ghawji al-Albani in his book Arkan al-Islam (2:620) very clearly states that "the issue is the arrival of aerosol, and whatever liquid turns to aerosol, into the lungs, namely the internal organ. As soon as it arrives, the status is that of breaking the fast; if it does not arrive inside, then there is no iftar."

2. The Hanbali fiqh scholar Muhammad b. Muhammad al-Mukhtar al-Shinqiti similarly noted that the bronchodilator vapor is essentially water being brought into the system and that there is Ijma` (Consensus) that even one drop of medicine dropped into the gullet breaks the fast, its being nutritive or not being meaningless. See the Arabic text here: - expired link (before 2023-02-04) ahlalhdeeth.com

The Sharia does not call for splitting hairs in order to be applied with clarity and peace of mind and, in this respect, the notion that something needs to be a nutrient to form a mufattir (fast-breaker) is an invented notion. I believe there is confusion or false qiyas here with the rule that a non-nutritive fast-breaking requires only qada' but not kaffara.

Note that he also draws the comparison of vapor and aerosol being no different from cigarette smoke with respect to being a distinct substance brought into the body through one of its natural openings. More on this below.

3. True, some Saudi scholars have allowed the inhaled medications for someone fasting based on their personal ijtihad, as has at least one pulmonary physician in Saudi Arabia. See:
http://www.jeddahboys.com/vb/JB139216.html
http://www.mktaba.org/vb/showthread.php?t=7685
http://www.okaz.com.sa/okaz/osf/20060924/Con2006092449901.htm

Since such goes against the mainstream position, its supporters have provided the weakest reasoning and excuses, such as analogy with the water residue that may reach the stomach from wudu' and siwak; or the "non-nutritive needle inserted for a phlebotomy"! This was cited by the Mufti of Egypt, Shaykh Ali Gomaa, whose fatwa is that it *does* break the fast. See:
http://mater90.jeeran.com/archive/2008/8/661397.html

Those who say it does not break the fast apparently want every asthmatic to fast like everyone else as if they were not ill. But such is far from the mainstream position, rather it is, in fairness, a fringe position.

4. At any rate, all this shows why it is far from clear exactly how those described as "erring on the side of precaution" are erring at all! Regardless, precaution is a reality and a priority in the Shariaa, so it is by default better than erring on the side of incaution, let alone when there is no erring at all but a mainstream stance on the one hand and a fringe stance on the other as far as one can see.

5. A very important misgiving is the notion that if one is too sick to fast, "they will be denied the barakat of Ramadan forever." On the contrary! Allah Most High has made it possible even for those who cannot fast in Ramadan due to sickness to get the full reward of those who fast _and more_.
How? Well, because actions are according to intentions, not according to results; and the medical inability to fast is a valid excuse not to, provided we follow the required course in such cases, namely, to give daily sadaqa as fidya for our fast. So, in addition to the reward of fasting, we also get an additional reward of sadaqa, plus we help our fellow man. This is exactly why, as the Prophet, upon him blessings and peace, said, "Allah Most High LOVES that His dispensations (rukhas) be followed JUST AS HE LOVES that His strict requirements be followed." Yet many people tend to over-emphasize strictness and dismiss dispensation as uninformed or even irreligious.

6. As for the cigarettes being bad there is no debate, but it is a completely separate issue. The pivot of proof in this particular discussion is wilful inhalation and this is why the comparison is extremely apt. This is something everybody understands. Even those who reject the haramness and even makruh aspect of cigarette smoking still agree that inhaling cigarette smoke constitutes a breach of the fast; and thus hardened Muslim smokers all over the world will refrain from smoking in Ramadan only because of that, not because of it being qabih, harmful or what not. Even Christians in Arab countries know this in Ramadan.

If you walk into a flour mill and deliberately inhale a cloud of flour it will break the fast also; so will deliberately sniffing incense for that matter--lest the nutrition aspect is brought up again--and all this is mentioned in the books of fiqh.

7. There is no doubt in my mind that an inhalator-dependent asthmatic who might die if deprived of the inhalator for too long, ails from an illness and has a valid excuse not to fast, even a lifelong excuse. I wonder if anyone denies this? Yet, so many people with valid and patent excuses not to fast, doubt the rahma granted by Allah and refuse His bounties in the form of reward for valid intentions, insisting that they must and will fast in order for those bounties to reach them, i.e. Allah Most High is unable to bless them otherwise--subhan Allah. So you will see diabetics, for example, rejecting their doctors' advice not to fast and going ahead at the risk of possibly fatal hypoglycemia. (See, e.g., http://www.al-inaam.com/library/DFASTING.HTM )

Allah Most High is not in need of such worshippers' misgivings about His dispensations, nor of their audacity with the gifts of health and life. And the saddest thing is to see doctors themselves deciding to be complicitous in this course, modifying the parameters of the Law in the name of ease or strictness (I am not sure which!), then gainsaying muftis for doing their job consciously and competently, just because the latter are not physicians! All this either shows a kind of hidden self-reliance and pride, or, at the very least, greater ignorance and misplaced piety than anything people accuse muftis of.

8. A possible solution could be for those using the inhalator and insisting that they want to fast to go ahead and fast, but at the same time to meet the daily fidya requirements of those who are excused from fasting, thus bringing over precaution to their side and setting their mind at rest. This way they both get the pleasure and socialization of fasting as well as ensure that their worship is 100% correct in sha Allah and valid by the criteria of all schools, short of which the shubha remains and, with it, at best, the suspicion of an invalid fast. And Allah Most High knows best.

Was-salam, GF Haddad