From the Guidelines
Methamphetamine testing is most accurately and commonly conducted through urine samples, which can detect use for 1-4 days after consumption, as supported by the most recent evidence 1. When considering methamphetamine testing, it's essential to understand the different methods available, including urine, blood, saliva, and hair samples.
- Urine tests are the most common method and can detect methamphetamine use for 1-4 days after consumption.
- Hair tests can detect use for up to 90 days, but are less commonly used due to factors such as hair growth rate, melanin content, and potential contamination.
- Blood and saliva tests have shorter detection windows of approximately 1-3 days. The testing process typically involves immunoassay screening followed by confirmatory testing using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) to eliminate false positives, as noted in 1. It's crucial to note that certain legal medications containing pseudoephedrine, such as some cold and allergy medications, can potentially cause false positive results, which is why confirmatory testing is essential, as highlighted in 1. If you need to undergo methamphetamine testing, it is recommended to avoid taking any over-the-counter medications containing pseudoephedrine for at least 48 hours before the test to prevent potential false positives, based on the most recent guideline evidence 1.
From the Research
Methamphetamine Testing
- Methamphetamine use continues to be an important public health problem, with increasing mortality associated with its use 2, 3
- Contingency management is among the most effective interventions for reducing methamphetamine use, with broad benefits including greater drug abstinence, higher utilization of other treatments and medical services, and reductions in risky sexual behavior 4
- The neurobiology of methamphetamine use disorder extends beyond the acute effect of the drug as a monoaminergic modulator and includes intracellular pathways focused on oxidative stress, neurotoxic and excitotoxic effects, and neuroinflammation 2
- There is no FDA-approved medication for methamphetamine use disorder, and current treatments include behavioral therapies such as cognitive behavioral therapy, behavioral activation, and contingency management 5, 2
Urinary Pharmacokinetics
- The urinary pharmacokinetics of methamphetamine and its metabolite, amphetamine, have been characterized after controlled oral administration to humans 6
- Maximum excretion rates ranged from 403 to 4919 microg/h for methamphetamine and 59 to 735 microg/h for amphetamine, with no relationship between dose and excretion rate 6
- The mean molar percentage of dose in the urine as total methamphetamine and amphetamine were 57.5 +/- 21.7% (low dose) and 40.9 +/- 8.5% (high dose) 6
Trends in Methamphetamine Use
- Methamphetamine use, methamphetamine use disorder, and associated overdose deaths have increased markedly in the US from 2015 to 2019 3
- The prevalence of methamphetamine use disorder without injection increased 105% from 2015 to 2019, and the adjusted prevalence of methamphetamine use disorder without injection more than tripled among certain demographic groups 3
- Risk factors for methamphetamine use, methamphetamine use disorder, injection, and frequent use included lower educational attainment, lower annual household income, lack of insurance, housing instability, criminal justice involvement, comorbidities, and polysubstance use 3