The irony is that paracetamol overdoses are far harder to treat and far more likely to lead to death or severe long term damage than opioid overdoses...
In the UK, codeine on it's own is still a controlled substance to the point where if you extracted the codeine from a single pill (possibly two, not sure of the exact limit) of the combination products, possession ould get you arrested, while you can go and buy packets with a total of 64 pills (32 each of ibuprofen and paracetamol combined with codeine) at the time from your local pharmacy no questions asked.
Basically there seems to be a bizarre belief that addicts will act as rational actors when faced with the knowledge of this mix, despite the fact that most other drug policy is based on the assumption that drug users - addicts or not - are incapable of making decisions about harm on their own.
This becomes even more bizarre in places like the UK, where there have been restrictions on the number of paracetamol pills that can be sold per transaction because of the amount of harm caused by accidental or intentional paracetamol overdoses.