This is a stupid, illogical and unnecessary rule which just makes life that bit more difficult for people who have a genine need to keep themselves well stocked with painkillers to be pain-free or at least reduce their pain in order to be able to live their lives.
There is a ridiculous rule about not being able to buy more than 2 packets of painkillers at once – no matter what the size is, or the type of painkiller, and it makes absolutely no sense whatsoever. It means I could buy 2 x 50 paracetomol…… but not 3 x 20….. it means I can't buy 2 x 12 paracetomol and 2 x 12 ibuprofen, even though these are different drugs that work in different ways and can be used together quite safely. It means that if you need to take painkillers regularly, e.g. for arthritis, you are forever having to buy them instead of being able to buy a decent supply in one go. It is mindless nonense! If it is meant to protect people at risk of overdose – rubbish – I could go to 3 shops in the same street which all sell paracetomol say, and buy more than enough that way to kill myself! Frankly, if you are suicidal, a stupid rule like this is very unlikely to hinder you.