Reading this I could not help but think of compliance and treatment safety for self-managed dosing.

It's evident, for example, that drugs such as Paracetamol (Tylenol for you Americans) should be dosed by body weight in children. To make life simpler for parents, they are given age and/or weight brackets, sometimes along with upper thresholds (e.g. mg/day).

This of course means that lighter children are comparatively over-dosed and heavier children under-dosed compared to a median.

The problem is - I think this works pretty well as a safeguard against dangerous over-dosing (i.e. liver toxicity etc.).

Now how would we turn that advice into a gradual dosing recommendation? We can use mg/kg body weight as is done e.g. in antibiotics. But that carries the potentially fatal risk of miscalculation, and some parents might intentionally overdose over a wrong risk perception.

What we would need is something like an exponential risk curve, indicating a "safe zone" and a "danger zone" while highlighting some critical threshold. This again would need to be age/weight-specific.

Do we think parents would be deterred from giving a kid too high of a paracetamol dose? I'm not so sure, especially over time.

So in the end, I think that in some cases (especially with self-administered dosing) round numbers and sharp thresholds may work well to mitigate fatal risks, even while increasing nonfatal risks.

First, many people are ... let's politely call it arithmetically challenged. They won't understand how to compute the amount and then obtain the correct dose. A chart or a table might have more success than a formula, no matter how simple the formula.

Then again, the dangers of paracetamol overdose aren't high (and I would think it's less for children than for adults). It's typically only needed for a few days. Perhaps that's where the stress should go: stop as soon as you can.