True-negative results occur when a patient is not taking the medication as prescribed and there is no drug present in the urine sample, or when the drug is metabolized so rapidly that the metabolites are eliminated before they can be detected.
How can a drug test come back negative?
When a drug is present in such high concentrations that there are no more binding sites left on the antibody, the sample may present with falsely low values. If the low value is below the test cutoff, the result will be negative.
How common is a false negative on a drug test?
Drug tests generally produce false-positive results in 5% to 10% of cases and false negatives in 10% to 15% of cases, new research shows.
Can an at home drug test show a false negative?
No. No drug test of this type is 100% accurate. There are several factors that can make the test results negative even though the person is abusing drugs. First, you may have tested for the wrong drugs.
Why did my drug test come back negative diluted?
So, in short, a negative dilute result means that the donor was exceptionally hydrated at the time of the test; and the urine, and everything else it contained, was diluted. What’s tricky with a negative dilute test result is that it’s unknown why the concentration of the specimen was dilute.
What happens if my drug test comes back positive?
If the test results in a positive reading, meaning there is drug residue in the body, the results are forwarded to a medical review officer, who reviews the results and looks for any possible valid medical explanation for the results.
What would make a urine drug test invalid?
Invalid result: Refers to the result reported by a laboratory for a urine specimen that contains an unidentified adulterant, contains an unidentified interfering substance, has an abnormal physical characteristic, or has an endogenous substance at an abnormal concentration that prevents the laboratory from completing …
Can b12 cause false positive drug test?
Vitamin B Supplements
This can cause traces of THC to show up on a drug test.
Can energy drinks cause a failed drug test?
It is true there is a possibility that the urine of a person who consumed Red Bull or another energy drink can falsely test positive on an immunoassay drug test if the amino acids found in the drink mimic the structure of a certain drug.