Appearance of the metabolite, amphetamine, in oral fluid, plasma, and urine was highly variable and occurred in the range of 1— National Institute on Drug Abuse, September As a result of drug accumulation, most urine specimens for this subject were positive at the DHHS confirmation cutoff concentration throughout the 4 days of dosing and for approximately 46 h following the last dose. Thus, both detection times and detection rates are useful in interpretation of drug tests. A saliva swab can detect methamphetamine for days after the last dose was taken. Specimens for this subject continued to test positive for approximately 24 h following the fourth dose.
A total of 25 specimens were positive for methamphetamine at 2.
Methamphetamine Disposition in Oral Fluid, Plasma, and Urine
In addition, excess water intake can dilute urine and drug concentration and produce negative tests, whereas dehydration can concentrate urine. Methamphetamine concentrations in oral fluid specimens from subject BB were approximately threefold higher than for subject AA. Mean oral fluid concentrations of methamphetamine METH and amphetamine in five subjects following single-dose oral administration of 10 and 20 mg methamphetamine. Extending the detection periods to 0—48 and 0—72 h tended to diminish rates. A summary of C maxT maxand time to first positive methamphetamine and metabolite amphetamine specimens in oral fluid, plasma, and urine is shown in Table 1. Author manuscript; available in PMC Jul Mixing Meth and Alcohol.