Is correct dosage of drugs based on weight of who is assuming them?

[Josair]

For some drugs (read: ketamine), I always thought that the dosage is weight dependent, and I've always followed those guidelines.
Still, now I'm perplexed. In my whole life, the only time that a doctor decided the quantity of drug based on my weight was when I undergone surgery under general anesthesia, and I never read of doses as being weight-dependent when talking of other recreational drugs (MDMA, cocaine, cathinones, opiates, weed, etc)

So, when is it sensible to consider the dosage of a drug as mg/kg? For which RoA does it make more sense? I am now inclined to think that it could make more sense for oral administration than for IM, IV, nasal or rectal. Am I mistaken?
Thanks alot!

 

[opium]

doctors have your charts so they automatically give you a dosage based on the height and weight your listed as.

They dont ask, which would lead you to believe that it wasnt a factor.

For recreational, it is based on weight. the Recommended dose that everybody goes by, is for the average person. If your 6ft4 500lbs, the average dose wont do it for you. If yur 3ft2 85lbs, the average dose could be dangerous.

theres been plenty of times, because im not a really big kid (5ft10 150lbs) that someone gave me xanax, and had said "1mg should do it, it works for me and my friends" and i end up hardcore blacking out from just 1mg.

 

[Cane2theLeft]

^ good response.

Doctors usually factor in dosages without telling you but there is also less variability with a lot of treatments so unless someone is far from the medians (e.g. age, height, weight, etc.) then they will not need adjustments. 5mg of vicodin is enough for moderate pain for most people in society (cue EVERY bluelighter saying they needed way more than that to start - of course you did because you are all predisposed to being junkies and are not most people in society!).

When it comes to recreational dosages, the window closes quite a bit and more tailored dosing may become either more advantageous or seriously more necessary. Nearly no one in society risks death from 5mg of vicodin, they really just risk not getting enough pain relief, experiencing a little nausea or getting high. If someone wants to be nodding and drooling on their keyboards, then they are putting themselves much closer to risking death and precision in dosing becomes much more vital.