oldcarl
Greenlighter
Hi all,
I'm working on a calculator/pet-project of mine that will give a rough estimate of current ng/ml concentration of a certain drug metabolite in the urine based on dosing intervals. I've come here to see if anyone can poke holes in my theory below:
NOTE: This applies only to highly lipophilic chemicals with hepatic metabolism and renal excretion. I'm assuming that attempting any sort of application of this theory to chemicals such as THC would be many times more easily wrought with failure. Also, disclaimer, I don't know SHIT about science other than what I've read online, so if you're here attempting to pass a drug test, move along until we have a better understanding of whether my thinking is correct.
So, here's my theory: We can take the half-life of a chemical, and extrapolate this information to each multiple of that figure to find the amount of metabolite excreted and amount of metabolite still left to excrete within the body. For example, if we take a chemical such as hydrocodone (half-life maximum in healthy individuals of 6 hours) and examine a loading dose of 30mg (30000000 nanograms), and know the average male bladder size at full "I gotta take a piss!" capacity will conservatively be 400ml (sorry ladies, I'm a guy, plug in your average accordingly) we would figure the urine concentrations in ng/ml at the following levels at each six hour period:
T+6 = (30000000/2) = 15000000 and 15000000/400 = 37500ng/ml
T+12 = (15000000/2) = 7500000/400 = 18750ng/ml
T+18 = (7500000/2) = 3750000/400 = 9375ng/ml
...
So, you can likely see the application to SAMHSA cutoff levels and figuring whether or not you'll pass that urinalysis if this is at all accurate.
As far as application to passing a drug test goes, this does not take into account all variety of factors that could contribute to an increased dilution factor in the urine and therefore higher percentage chance of being below the cutoff levels. For instance, higher dilution of urine (a/k/a going in there with a bladder about to burst) could conceivably contribute another ~50ml to the dilution of the baseline ng in the urine sample. In addition, distribution of the chemicals throughout an individual's urine is likely not even, and there may be pockets of higher concentraions/lower concentrations within a bladderful of piss. Those, among many other things, could have you better/worse off when it comes down to the wire, that's why I have usedaverage bladder capacities, and maximum elimination half-lives to sort of give what I consider the "worst case" scenario for someone with slow metabolism and who can't hold ten ounces of urine with no issue like I can!
Anyway, let me know what you smarter guys think - this is just something I came up with while laying in bed this morning and I wrote a little program for it that I'll share with the community
I'm working on a calculator/pet-project of mine that will give a rough estimate of current ng/ml concentration of a certain drug metabolite in the urine based on dosing intervals. I've come here to see if anyone can poke holes in my theory below:
NOTE: This applies only to highly lipophilic chemicals with hepatic metabolism and renal excretion. I'm assuming that attempting any sort of application of this theory to chemicals such as THC would be many times more easily wrought with failure. Also, disclaimer, I don't know SHIT about science other than what I've read online, so if you're here attempting to pass a drug test, move along until we have a better understanding of whether my thinking is correct.
So, here's my theory: We can take the half-life of a chemical, and extrapolate this information to each multiple of that figure to find the amount of metabolite excreted and amount of metabolite still left to excrete within the body. For example, if we take a chemical such as hydrocodone (half-life maximum in healthy individuals of 6 hours) and examine a loading dose of 30mg (30000000 nanograms), and know the average male bladder size at full "I gotta take a piss!" capacity will conservatively be 400ml (sorry ladies, I'm a guy, plug in your average accordingly) we would figure the urine concentrations in ng/ml at the following levels at each six hour period:
T+6 = (30000000/2) = 15000000 and 15000000/400 = 37500ng/ml
T+12 = (15000000/2) = 7500000/400 = 18750ng/ml
T+18 = (7500000/2) = 3750000/400 = 9375ng/ml
...
So, you can likely see the application to SAMHSA cutoff levels and figuring whether or not you'll pass that urinalysis if this is at all accurate.
As far as application to passing a drug test goes, this does not take into account all variety of factors that could contribute to an increased dilution factor in the urine and therefore higher percentage chance of being below the cutoff levels. For instance, higher dilution of urine (a/k/a going in there with a bladder about to burst) could conceivably contribute another ~50ml to the dilution of the baseline ng in the urine sample. In addition, distribution of the chemicals throughout an individual's urine is likely not even, and there may be pockets of higher concentraions/lower concentrations within a bladderful of piss. Those, among many other things, could have you better/worse off when it comes down to the wire, that's why I have usedaverage bladder capacities, and maximum elimination half-lives to sort of give what I consider the "worst case" scenario for someone with slow metabolism and who can't hold ten ounces of urine with no issue like I can!
Anyway, let me know what you smarter guys think - this is just something I came up with while laying in bed this morning and I wrote a little program for it that I'll share with the community
