Brief Answer:
sudafed can give false positive result

Detailed Answer:
Hi
I looked into the research and i think the culprit that can give false positive for Methamphetamine would be Sudafed.

I will give you long list of agents that are likely to result in false positive for Methamphetamine. Ephedrine, pseudoephedrine, propylephedrine, phenylephrine, or desoxyephedrine,
Phenegan-D, Robitussin Cold and Flu, Vicks Nyquil. Over-the-counter diet aids with phenylpropanolamine.
Prescription medications:
(Amfepramone, Cathne, Etafediabe, Morazone, phendimetrazine, phenmetrazine, benzphetamine, fenfluramine, dexfenfluramine, dexdenfluramine, Redux, mephentermine, Mesocarb, methoxyphenamine, phentermine, amineptine, Pholedrine, hydroymethamphetamine, Dexedrine, amifepramone, clobenzorex, fenproyorex, mefenorex, fenelylline, Didrex, dextroamphetamine, methphenidate, Ritalin, pemoline, Cylert, selegiline, Deprenyl, Eldepryl, Famprofazone.

This is long list which i have got from the research.

hopefully if you give this information to the people who are conducting test, they may reschedule the test and you be sure that before hand to avoid this medication, that is the reason i have put here a long list.

Take care.

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Brief Answer:
To my knowledge sudafed only.

Detailed Answer:
Hi,

There are reports suggesting naproxen can interfere with urine drug screening test. But it is not specific for methamphetamine. So to the best of my knowledge only sudafed has potentials to cause false positive methamphetamine results.

I suggest you to disclose your drug history to the testing authority before undergoing test.

Hope this information in some way helpful to you.
Take care.

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