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High-throughput and Comprehensive Drug Surveillance Using Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry

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Famprofazone use can be misinterpreted as methamphetamine abuse.

Kuei-Hui Chan¹, Mei-Chich Hsu, Chen-Yu Tseng

¹Graduate Institute of Coaching Sciences, National Taiwan Sport University, Kweishan, Taoyuan 33301, Taiwan. quenhuen@gmail.com

Journal of Analytical Toxicology

|July 29, 2010

Summary

This summary is machine-generated.

Famprofazone, an analgesic, metabolizes into methamphetamine (MA) and amphetamine (AM). This study found that legitimate famprofazone use can lead to positive MA drug tests, potentially misidentifying users as abusers.

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Area of Science:

Forensic Toxicology
Pharmacology

Background:

Famprofazone, a component of Gewolen, is an analgesic.
Metabolism of famprofazone yields methamphetamine (MA) and amphetamine (AM).
Positive MA tests in Taiwan can lead to misinterpretation of legitimate famprofazone users as illicit drug abusers.

Purpose of the Study:

To determine if a single dose of famprofazone can result in urine MA concentrations exceeding Taiwan's controlled substance regulations.
To investigate the potential for misidentification of legitimate famprofazone users as methamphetamine abusers.

Main Methods:

Six subjects received a single 25 mg dose of famprofazone.
Urine specimens were collected over 48 hours post-administration.
Screening by immunoassay followed by confirmation with gas chromatography-mass spectrometry (GC-MS).

Main Results:

Urine MA and AM concentrations ranged from 901-2670 ng/mL and 208-711 ng/mL, respectively.
18.8% of samples exceeded 500 ng/mL for amphetamines via immunoassay.
Positive MA (>or= 500 ng/mL) and AM (>or= 100 ng/mL) results were observed within 2-34 hours, meeting Taiwan's legal thresholds.

Conclusions:

Legitimate famprofazone use can produce urine MA and AM levels that trigger positive results under current Taiwanese regulations.
There is a significant risk of misclassifying individuals using famprofazone as illicit methamphetamine abusers.
Current drug testing regulations may require re-evaluation to distinguish therapeutic famprofazone use from illicit MA abuse.