Fair enough, and kind of what I meant. Lithium just has a narrow therapeutic window, and can get quite toxic from just going on a ski vacation (high altitude).
Anti-psychotics can have some nasty side-effects, but I'm not saying people shouldn't take them.
It's just risk/benefit.
Aspirin is more of a risk for ulcers in some people, they might take ibuprofen for pain instead.
But acetominophen/Tylenol is not the best med for pain in the first place, not any better than ibuprofen, aspirin, naproxen, other COX inhibitors, and yet can do a lot of damage to your liver, or be fatal. Really it shouldn't be on the market at all, definitely not in combo pills.
But marketing means you've heard of, and want, Vicodin for your wisdom teeth. You say, WTF is Vicoprofen? It's on the market, generic, available, hydrocodone plus ibuprofen. Marketing and idiot junkies made you want the Tylenol-containing med.
OP had a headache and couldn't sleep, one Unisom (diphenhydramine) would help, but Johnson & Johnson thinks she should include a whole gram of their poison with it, half the daily limit--they seal two pills together in the blister pack. They really scored a marketing victory there, better than Coca-Cola.