As far as shelf life goes (assuming you're able to stockpile some meds
Medical authorities state that expired medicine is safe to take, even those that expired years ago. It's true the effectiveness of a drug may decrease over time, but much of the original potency still remains even a decade after the expiration date. Excluding nitroglycerin, insulin, and liquid antibiotics, most medications are as long-lasting as the ones tested by the military. Placing a medication in a cool place, such as a refrigerator, will help a drug remain potent for many years.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7040264/