Substances Known to Metabolize to Methamphetamine and Amphetamine

Many medications and substances are known to metabolize to methamphetamine or amphetamine, thus giving analytical true positives (Table 2). If a patient is on one of these medications, the positive result is a clinical false positive. Enantiomeric analysis may be useful in verifying that the positive result was due to the use of a prescription drug. For example, selegiline, a drug used in the treatment of Parkinson's

Table 2

Examples of Amphetamines-Containing products3

Amphetamines-containing Products

Substances known to contain d-amphetamine or d,/-amphetamine

Substances known to contain d-methamphetamine

Substances known to contain /-methamphetamine

Substances known to metabolize to methamphetamine (and amphetamine)

Substances known to metabolize to amphetamine





Vicks Inhaler®

Benzphetamine (Didrex®)





Selegiline (Eldepryl®)






Mefenorex a Medical Review Officer Manual for Federal Agency Workplace Drug Testing Programs http:// (Effective%20November% 201,%202004).aspx (accessed 11/05/2006).

disease, is metabolized to /-methamphetamine (and /-amphetamine) without any racem-ization during metabolism (7). Given the immunospecificity of most amphetamines immunoassay is mostly directed toward d-methamphetamine, and given the fact that /-methamphetamine and /-amphetamine concentrations derived from selegiline metabolism are relatively low, urine specimens of patients on selegiline most likely would not test positive. Should there be a positive initial test, enantiomeric analysis should show the presence of only the /-isomer if the patient has taken selegiline (5). Clobenzorex is metabolized to d-amphetamine. Therefore, enantiomeric analysis should show only d-amphetamine; the presence of the /-amphetamine is inconsistent with the sole use of clobenzorex (8).

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Defeat Drugs and Live Free

Being addicted to drugs is a complicated matter condition that's been specified as a disorder that evidences in the obsessional thinking about and utilization of drugs. It's a matter that might continue to get worse and become disastrous and deadly if left untreated.

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