It has to do with acuity of symptoms and duration of action mostly. There’s how long something works, and then there’s how easy it is to notice when it’s not working.
Beta blockers (the ones that end in -olol) tend to be some of the more dramatically noticed ones. They work about 12-24 hours, depending on the exact drug, and then they wear off. Since their job is to keep your heart rate lower, that means when the run out, your heart beats faster, and many people feel that as anxiety. Of course, your pressure goes up, too. So the beta blockers are pretty important to take regularly. That’s the one they’re most likely to want to get into you on schedule should you go into the hospital. If they can’t do it by mouth, they’ll often resort to an IV.
Diuretics (which you don’t mention, but are often used to control blood pressure) are next. Many people can get away with skipping a day or two, but then the water starts to retain at a noticeable level. Feet and ankles get poofy, breathing maybe gets a little harder. But I’ve known some people who can go a week or longer; these people probably need to have a chat with their doctor about whether an every-other-day dose or a “PRN” (when you need it) dose might be better for them, instead of an every day medicine.
Calcium channel blockers come in two “generations”. First generation (verapamil, nifedipine, and diltiazem) only last about 10-12 hours, and then the blood pressure will go up. Second generation amlodipine takes much longer to start working (3-4 days), and lasts a long time once you’ve reached the “steady state” where the excretion matches the intake. Once you’ve been taking it regularly, you may be able to miss three or four days without terrible effects. Other second generation CCBs )felodipine, nisoldipine) last about 24 hours. But it’s a lot harder for most people to notice that CCBs aren’t working anymore - there’s no increased heart rate or water retention as a signal. There’s just high blood pressure, which is largely without symptoms (until it’s REALLY bad.)
Angiotensin receptor blockers are pretty complex. They help relax the blood vessels and also influence the kidney hormones to secrete more water in the urine (but not quite as dramatically as diuretics do). Telmisartan is the longest acting of them, with a half life of 24 hours. So you can miss a day or two before your pressure will start to go up, but you may not notice it at first. If you pay attention to your pee, you’ll probably notice it’s more concentrated.
Rosuvastatin has a half life of 19 hours. And again, its effects are not really noticeable in the moment. Will missing a few days impact your cholesterol? Yes…but you’re probably not going to notice that. There are no symptoms. Statins are often skipped should you have a short hospital stay.
Aspirin prevents platelets from sticking together to clot your blood, and that lasts as long as the platelet lasts, about 10 days. So you can miss that one for more than a week before your clotting risk is back to normal. If you were to cut yourself every day and time the clotting, it would gradually clot faster and faster, as new platelets are made everyday. Somewhere in there would be the “no longer therapeutic” level, but what that level is depends on you and your risk factors. If you’re at high risk for blood clots, don’t miss your aspirin. But if you go into the hospital (for something other than a clot), don’t be surprised if the nurse is a little casual about getting you your aspirin. It will be put on your medication list eventually, but it’s not going to be the first priority.