- You can stockpile your prescriptions. Ask you doctor for 90 day prescription refills instead of 30 day refills. You can also ask you doctor for additional prescriptions (like a prescription for antibiotics even if you don't need it if they are sympathetic to your survivalist tendencies YMMV).
- You can use veterinary meds meant for animals. This isn't recommended by anyone in the medical field for a number of reasons but if it is 'take an antibiotic meant for your animal or die', well, YMMV again.
- You can work to get off your meds. Again, the medical field can be quite divisive and when the spouse, who was already on a bunch of meds and not in any hurry to get off them, was prescribed a whole bunch of additional meds for a heart attack/stents/etc, suddenly had a change of heart--no pun intended--and after years of me harping on the WFPB vegan diet for completely getting off of all meds, then told the cardiologist that the goals was to get completely off all meds (except blood thinners which are necessary for a period of time when you have new cardiac stents), the cardiologist just laughed. No one ever did that he said. Well he will soon know at least one person who did this as a complete change of diet has nearly reversed the spouse's diabetes and I am guessing that after a new set of blood tests it may show that the meds for high cholesterol and high blood pressure may no longer be needed either. There are several doctors who are completely on board with using diet to fix what are considered lifelong, chronic medical problems including Dr Gregor, Dr Fuhrman, and Dr McDougall.
As with anything medical related, you need to know what you are doing lest you cause permanent damage or death. And seeking medical advice from a doctor or pharmacist is always a good idea as well as copious amounts of research on your part. There are some meds you simply cannot get off of no matter how you change your diet (some psych meds, etc) and while vet meds might work in a pinch, they might not depending on the source of the meds, the impurities that wouldn't be found in human meds, etc.