No, it won’t. But not all suicides are from people who are really determined to kill themselves. Every little step you put in the way gives people a chance to reconsider.
Blister packs really are there as a suicide prevention method:
From there:
“And again, you’d think all I have to do is go to six drugstores, you know, buy packets in each of them, all I have to do is just tear them out. But it has cut down the number of overdoses. It’s also cut down the number of serious overdoses that have led to kidney damage. Now, very few people died of an acetaminophen overdose. So it’s been hard to document that it cut the number of deaths, but certainly the number of attempts. The overdoses with it have been cut dramatically.”
All other medications you can easily overdose with are in blister packs, not just this one, so the same barriers are in place for every easy-to-access drug. You can also only get large amounts of paracetamol/tylenol on prescription.
The situation you describe, where someone ends up taking maybe twice the dose of paracetamol once or twice over a few days of illness, really isn’t serious enough to count as an overdose and is hugely unlikely to end up in a hospital admission. It could be an issue if you do it every day for weeks on end, though, and might be one of the other reasons for choosing blister packs as the norm in the UK.