Aye. Getting old does so beat the alternative.
If it’s a prescription strength, and you’re forced to get it mail-order, and the doctor’s office screws up with the refill, it can happen. Or if you’re out of town, combined with the above (or you’re careless).
Luckily, an OTC version will fill the gap temporarily.
I’ve come close to running out of a couple of meds that do NOT have OTC equivalents, due to the doctor’s office accidentally sending in a refill for HALF THE DOSE. And when you get it mail-order, and just toss the new bottles in with the old without looking too carefully, and thus don’t catch the doctor’s error right away… This has happened to me on at least 3 different occasions.