An approved drug for moderate conditions of any sort is not likely to harm you. A prophylaxis used in acute circumstances is by definition unlikely to harm you. It is not impossible that you will not be harmed by acute use of a prophylaxis but it is wildly unlikely since by definition a prophylaxis is taken to prevent a bad outcome that you might never experience in the first place, and thus its risk of harm must be measured against null rather than some condition.
For example Ivermectin is used prophylactically against parasitic infection in many nations. HCQ is used prophylactically against malaria. Neither parasitic infection or being bitten by a mosquito carrying malaria is a certainty; ergo, both must be extremely safe to use this way on a chronic basis because the risk of the bad thing they defend against is not certain.
Both are approved drugs that have gone through the full FDA certification process and have decades of experience associated with them. Likewise Budesonide is also fully FDA approved and is used for chronic conditions in which it is judged to be reasonably safe. Used for an acute exposure it would be extraordinarily unlikely to harm you since people use it for years without ill effect while you propose to use it for days.
We knew within the first few months that when *****-19 gets you in a bad way it is a thrombotic and endothelial event. We have known how to treat those sorts of conditions for decades. We also knew that ventilators, for example, would be worthless in such an event because the issue isn't gas exchange which they can address -- it is oxygen transport by the blood as a result of the thrombotic state. If there is no ordinary flow of blood due to such shoving gas under pressure into the lungs can only do harm, and indeed it does. We knew by APRIL OF 2020 that ventilators did not work not only by the mechanism of damage of people who got hit hard in this disease but also by direct experience in Wuhan, which I wrote up at the time -- you died nearly all of the time if one was used.
HHS did within weeks and still does today pay an extra bonus to a hospital for using a "treatment" that on the science was known to be worthless at best and might directly kill you within weeks of *****-19 becoming a "discovered issue" in the United States. Here we are nearly two years later and we are literally paying a bounty for toe tags and the hospitals and doctors are lapping up the money.