Hydrochlorothiazide (HCTZ) is detectable in a urine screen for
many days after the medication has last been ingested. The drug
screen must include a test for the HCTZ for it to be detected. This
test is commonly included in drug screens as some people will use
HCTZ in an attempt to flush illegal substances from their system.
HCTZ is a prescription drug, although, it is not a "controlled
substance."