It be nice to store away some antibiotics too. Not sure the store time on those, but I guess you could store them away in a cool dry place, probably prolong the store date a bit. Thing is where the fuck do you get them though, lol.
I guess when shit goes down shit like this will be the first thing the smart people will loot for. and later this will be worth its weight in gold.
1. Go to doctor with possible infection
2. Get prescribed antibiotics
3. Fill prescription
4. Don't take them because you don't think it's an infection, the dr is just a lazy pill pusher, and they fuck up your stomach
5. Profit.
Like you said, I don't know the shelf life of them, but I'm pretty sure they don't get toxic when they get old. Probably just lose effectiveness. Maybe sometime down the road you get a real infection and use these older pills to rotate out the stock.