Table of Contents
What can cause a false negative on a urine drug test?
False-negatives can occur when the urine drug concentration is below the threshold level set by the laboratory performing the test. Dilute urine, the duration of time between ingestion of the drug and time of testing, and the quantity of the drug ingested may affect the occurrence of false-negatives.
Why is my drug test negative?
Immunoassays are based on the binding of an antibody and antigen. 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.
Do you want negative or positive on a drug test?
A positive result means that one or more of the panel drugs were detected at a certain concentration. A negative result means that the panel drugs weren’t detected at the cut-off concentration, or at all.
Can an at home drug test be wrong?
Test results may be false negatives. Most drugs—other than marijuana—can be flushed from the user’s system in as few as 12 hours. Within 2 or 3 days, these drugs are almost always undetectable. Teens also may try to “cheat” on a urine test.
How to interpret a negative urine drug test?
Interpreting Negative Urine Drug Test Results. A positive test result showing drugs and/or metabolites found in urine is easily understood. A negative result, while initially simple to understand, can be more complicated and requires the clinician to be aware of several factors that can cause the urine sample to test negative for a compound.
What should I keep out of my urine test?
Keep the soap, salt, bleach, eye drops and other “homemade magic tricks” out from your urine sample. #2 Impede the cleansing process. Junk food, alcohol, nicotine, unnecessary medications, low activity, bad sleep cause the toxic things in your body to stay. The systems responsible for detoxications are working with overload.
What can you do with a urine drug test?
For information about the SORT evidence rating system, go to https://www.aafp.org/afpsort. Urine drug testing can be used to monitor compliance with prescribed therapy and detect the use of nonprescribed and illicit substances, especially opioids, benzodiazepines, and heroin. Immunoassays are subject to false-positive and false-negative results.
Can a doctor mask a positive drug test?
Urine samples can be adulterated with other substances to mask positive results on urine drug testing. Family physicians must be familiar with these substances, the methods to detect them, and their effects on urine drug testing. Urine drug testing is an important part of managing long-term opioid therapy.