Will a urine test for cocaine show positive 72 hours after cocaine usage?

A urine test for cocaine will be positive for up to 8 days after the last cocaine usage. It will show up in urine after approximately 4 hours after usage and will, on average, remain in the urine for 4-6 days. For larger doses, it will remain for 8-10 days.




Well, in fact it is unlikely to be positive longer than around 3-5 days of use unless you are a regular, heavy user. I tested negative for cocaine 3 days after using crack, although mine was a saliva test, other tests may detect for longer.