Can Vyvanse Cause A Positive Amphetamine Drug Test?

Answer

Vyvanse will certainly cause a positive test for amphetamine if you are taking a standard urinalysis drug test.

The active ingredient in Vyvanse is lisdexamfetamine, a prodrug of dextroamphetamine (d-amphetamine). A prodrug is simply a drug that requires metabolic activation to the active compound in the body.

In other words, after taking Vyvanse by mouth, lisdexamfetamine is converted to dextroamphetamine in the blood (due to the high hydrolytic activity of red blood cells). Dextroamphetamine is an 'amphetamine' and will product a positive result on urine drug tests.

What About Vyvanse Causing A Positive Methamphetamine Result?

In terms of testing positive for methamphetamine, while taking Vyvanse, that is possible based on a problem with "cross-reactivity" on urine drug screenings. However, it is important to distinguish that one byproduct of methamphetamine metabolism in our bodies is amphetamine, and you therefore will test positive for amphetamine on a drug test if you are taking methamphetamine.

Some drug tests do specifically look for methamphetamine as the parent compound too. It has been reported that many drugs, (including amphetamine products, Wellbutrin, and Zantac for example) have been known to cause "false positives" for methamphetamine.

Urinalysis False Positives

The main factor that causes false positives is the drug tests themselves. The most commonly utilized tests are immunoassay tests, such as the EIA (Enzyme-Linked Immunoassay) test. They work by utilizing antibodies to react to specific drug compounds, such as methamphetamine. When a specified compound (e.g. meth) is present in a test urine sample, an antibody binds to it and produces a reaction. When a reaction occurs, it is recorded as a 'positive' result.

However, many times drugs that are NOT being tested for can occasionally react with the wrong antibody (i.e. 'cross react'), resulting in a 'false positive'. This may have happened in your case. There are more accurate and definitive ways to test for drug compounds (such as gas chromatography) and if those options are available, be sure to ask your doctor or testing facility if they can be utilized.

Final Words

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