The average time that cocaine can be detected in the urine for a single use and a person who is of average weight around one hundred and fifty pounds is anywhere from two to seven days.  That is to say the detection time will vary depending on such factors as the amount of cocaine used, the frequency of the use of the drug, (chronic users will have the cocaine metabolites detectable in the urine for a much longer time) the person’s body weight and metabolism, the pH levels and concentration of the urine sample, or even such rare conditions as a kidney disease or kidney infection.  The cutoff level for cocaine metabolites in a urine drug test is one hundred and fifty nanograms per milliliter.  Anything above this level can be declared as a positive use of cocaine.  A level that has been found to be below one hundred and fifty nanograms per milliliter can be declared as a negative for cocaine use.  However, test performed for probationary purposes may have a zero tolerance level for cocaine metabolites, or zero nanograms per milliliter.  Some tests may have a lower tolerance as well.  For example, highly sensitive employment opportunities may have a lower tolerance level than the one hundred and fifty nanograms per milliliter that is the standard.  There are certain substances that can be construed as a false positive for cocaine use. Amoxicillin and some other antibiotics can provide a false positive for cocaine use.  Sometime a person who suffers from liver disease, kidney disease or diabetes can receive a positive result for cocaine use in a urine test.