Sure, but none of the drugs that would be used in the situation you describe would matter enough to kill or seriously harm anyone. At worst it would just have a longer half life and then you just don't give as many or as high doses later on. And that also applies to many different demographics including old people and people with other medical issues that causes them to clear drugs slower, which is why patients are monitored and dosed accordingly and the dosage schedule is a guideline not a rule.

If some random distribution of body fat could kill a person then you'd have people dropping dead left and right based off differences in everyone's muscle mass to body fat ratio and it just doesn't work that way.

I never said it was irrelevant, I literally wrote that it can be very very relevant in some cases, but it's not so relevant that it's vital to know if you're unconscious and bleeding out.